Change more ReadBytes

Fix null password on ReaderFactory.  Fix null options on SevenZipArchive

FORMATS.md

@@ -28,4 +28,5 @@ For those who want to directly compress/decompress bits
 | GZipStream | Both |
 | DeflateStream | Both |
 | LZMAStream | Both |
-| PPMdStream | Both |
+| PPMdStream | Both |
+| ADCStream | Decompress |

README.md

@@ -9,7 +9,7 @@ The major feature is support for non-seekable streams so large files can be proc
 ## Need Help?
 Post Issues on Github!
 
-Check the [Supported Formats](FORMATS.md) and [basic usage.](USAGE.md)
+Check the [Supported Formats](FORMATS.md) and [Basic Usage.](USAGE.md)
 
 ## A Simple Request
 
@@ -31,25 +31,36 @@ I'm always looking for help or ideas. Please submit code or email with ideas. Un
 
 ## Version Log
 
+### Version 0.13.1
+
+* [Fix null password on ReaderFactory. Fix null options on SevenZipArchive](https://github.com/adamhathcock/sharpcompress/pull/188)
+* [Make PpmdProperties lazy to avoid unnecessary allocations.](https://github.com/adamhathcock/sharpcompress/pull/185)
+
 ### Version 0.13.0
+
 * Breaking change: Big refactor of Options on API.
 * 7Zip supports Deflate
 
 ### Version 0.12.4
+
 * Forward only zip issue fix https://github.com/adamhathcock/sharpcompress/issues/160
 * Try to fix frameworks again by copying targets from JSON.NET
 
 ### Version 0.12.3
+
 * 7Zip fixes https://github.com/adamhathcock/sharpcompress/issues/73
 * Maybe all profiles will work with project.json now
 
 ### Version 0.12.2
+
 * Support Profile 259 again
 
 ### Version 0.12.1
+
 * Support Silverlight 5
 
 ### Version 0.12.0
+
 * .NET Core RTM!
 * Bug fix for Tar long paths
 

src/SharpCompress/Archives/GZip/GZipArchive.cs

@@ -4,6 +4,7 @@ using System.IO;
 using System.Linq;
 using SharpCompress.Common;
 using SharpCompress.Common.GZip;
+using SharpCompress.IO;
 using SharpCompress.Readers;
 using SharpCompress.Readers.GZip;
 using SharpCompress.Writers;
@@ -103,26 +104,28 @@ namespace SharpCompress.Archives.GZip
         public static bool IsGZipFile(Stream stream)
         {
             // read the header on the first read
-            byte[] header = new byte[10];
-            int n = stream.Read(header, 0, header.Length);
-
-            // workitem 8501: handle edge case (decompress empty stream)
-            if (n == 0)
+            using (var header = ByteArrayPool.RentScope(10))
             {
-                return false;
-            }
+                int n = stream.Read(header);
 
-            if (n != 10)
-            {
-                return false;
-            }
+                // workitem 8501: handle edge case (decompress empty stream)
+                if (n == 0)
+                {
+                    return false;
+                }
 
-            if (header[0] != 0x1F || header[1] != 0x8B || header[2] != 8)
-            {
-                return false;
-            }
+                if (n != 10)
+                {
+                    return false;
+                }
 
-            return true;
+                if (header[0] != 0x1F || header[1] != 0x8B || header[2] != 8)
+                {
+                    return false;
+                }
+
+                return true;
+            }
         }
 
         /// <summary>

src/SharpCompress/Archives/SevenZip/SevenZipArchive.cs

@@ -30,7 +30,7 @@ namespace SharpCompress.Archives.SevenZip
         /// </summary>
         /// <param name="fileInfo"></param>
         /// <param name="readerOptions"></param>
-        public static SevenZipArchive Open(FileInfo fileInfo, ReaderOptions readerOptions)
+        public static SevenZipArchive Open(FileInfo fileInfo, ReaderOptions readerOptions = null)
         {
             fileInfo.CheckNotNull("fileInfo");
             return new SevenZipArchive(fileInfo, readerOptions ?? new ReaderOptions());
@@ -44,7 +44,7 @@ namespace SharpCompress.Archives.SevenZip
         public static SevenZipArchive Open(Stream stream, ReaderOptions readerOptions = null)
         {
             stream.CheckNotNull("stream");
-            return new SevenZipArchive(stream, readerOptions);
+            return new SevenZipArchive(stream, readerOptions ?? new ReaderOptions());
         }
 
 #if !NO_FILE
@@ -141,8 +141,10 @@ namespace SharpCompress.Archives.SevenZip
         private static bool SignatureMatch(Stream stream)
         {
             BinaryReader reader = new BinaryReader(stream);
-            byte[] signatureBytes = reader.ReadBytes(6);
-            return signatureBytes.BinaryEquals(SIGNATURE);
+            using (var signatureBytes = reader.ReadScope(6))
+            {
+                return signatureBytes.BinaryEquals(SIGNATURE);
+            }
         }
 
         protected override IReader CreateReaderForSolidExtraction()

src/SharpCompress/Common/GZip/GZipFilePart.cs

@@ -5,6 +5,7 @@ using SharpCompress.Common.Tar.Headers;
 using SharpCompress.Compressors;
 using SharpCompress.Compressors.Deflate;
 using SharpCompress.Converters;
+using SharpCompress.IO;
 
 namespace SharpCompress.Common.GZip
 {
@@ -36,79 +37,85 @@ namespace SharpCompress.Common.GZip
         private void ReadAndValidateGzipHeader(Stream stream)
         {
             // read the header on the first read
-            byte[] header = new byte[10];
-            int n = stream.Read(header, 0, header.Length);
-
-            // workitem 8501: handle edge case (decompress empty stream)
-            if (n == 0)
+            using (var header = ByteArrayPool.RentScope(10))
             {
-                return;
-            }
+                int n = stream.Read(header);
 
-            if (n != 10)
-            {
-                throw new ZlibException("Not a valid GZIP stream.");
-            }
-
-            if (header[0] != 0x1F || header[1] != 0x8B || header[2] != 8)
-            {
-                throw new ZlibException("Bad GZIP header.");
-            }
-
-            Int32 timet = DataConverter.LittleEndian.GetInt32(header, 4);
-            DateModified = TarHeader.Epoch.AddSeconds(timet);
-            if ((header[3] & 0x04) == 0x04)
-            {
-                // read and discard extra field
-                n = stream.Read(header, 0, 2); // 2-byte length field
-
-                Int16 extraLength = (Int16)(header[0] + header[1] * 256);
-                byte[] extra = new byte[extraLength];
-                n = stream.Read(extra, 0, extra.Length);
-                if (n != extraLength)
+                // workitem 8501: handle edge case (decompress empty stream)
+                if (n == 0)
                 {
-                    throw new ZlibException("Unexpected end-of-file reading GZIP header.");
+                    return;
+                }
+
+                if (n != 10)
+                {
+                    throw new ZlibException("Not a valid GZIP stream.");
+                }
+
+                if (header[0] != 0x1F || header[1] != 0x8B || header[2] != 8)
+                {
+                    throw new ZlibException("Bad GZIP header.");
+                }
+
+                Int32 timet = DataConverter.LittleEndian.GetInt32(header.Array, 4);
+                DateModified = TarHeader.Epoch.AddSeconds(timet);
+                if ((header[3] & 0x04) == 0x04)
+                {
+                    // read and discard extra field
+                    n = stream.Read(header.Array, 0, 2); // 2-byte length field
+
+                    Int16 extraLength = (Int16)(header[0] + header[1] * 256);
+                    using (var extra = ByteArrayPool.RentScope(extraLength))
+                    {
+                        n = stream.Read(extra);
+                        if (n != extraLength)
+                        {
+                            throw new ZlibException("Unexpected end-of-file reading GZIP header.");
+                        }
+                    }
+                }
+                if ((header[3] & 0x08) == 0x08)
+                {
+                    name = ReadZeroTerminatedString(stream);
+                }
+                if ((header[3] & 0x10) == 0x010)
+                {
+                    ReadZeroTerminatedString(stream);
+                }
+                if ((header[3] & 0x02) == 0x02)
+                {
+                    stream.ReadByte(); // CRC16, ignore
                 }
-            }
-            if ((header[3] & 0x08) == 0x08)
-            {
-                name = ReadZeroTerminatedString(stream);
-            }
-            if ((header[3] & 0x10) == 0x010)
-            {
-                ReadZeroTerminatedString(stream);
-            }
-            if ((header[3] & 0x02) == 0x02)
-            {
-                stream.ReadByte(); // CRC16, ignore
             }
         }
 
         private static string ReadZeroTerminatedString(Stream stream)
         {
-            byte[] buf1 = new byte[1];
-            var list = new List<byte>();
-            bool done = false;
-            do
+            using (var buf1 = ByteArrayPool.RentScope(1))
             {
-                // workitem 7740
-                int n = stream.Read(buf1, 0, 1);
-                if (n != 1)
+                var list = new List<byte>();
+                bool done = false;
+                do
                 {
-                    throw new ZlibException("Unexpected EOF reading GZIP header.");
-                }
-                if (buf1[0] == 0)
-                {
-                    done = true;
-                }
-                else
-                {
-                    list.Add(buf1[0]);
+                    // workitem 7740
+                    int n = stream.Read(buf1);
+                    if (n != 1)
+                    {
+                        throw new ZlibException("Unexpected EOF reading GZIP header.");
+                    }
+                    if (buf1[0] == 0)
+                    {
+                        done = true;
+                    }
+                    else
+                    {
+                        list.Add(buf1[0]);
+                    }
                 }
+                while (!done);
+                byte[] a = list.ToArray();
+                return ArchiveEncoding.Default.GetString(a, 0, a.Length);
             }
-            while (!done);
-            byte[] a = list.ToArray();
-            return ArchiveEncoding.Default.GetString(a, 0, a.Length);
         }
     }
 }

src/SharpCompress/Common/Rar/Headers/FileHeader.cs

@@ -47,81 +47,82 @@ namespace SharpCompress.Common.Rar.Headers
 
             nameSize = nameSize > 4 * 1024 ? (short)(4 * 1024) : nameSize;
 
-            byte[] fileNameBytes = reader.ReadBytes(nameSize);
-
-            switch (HeaderType)
+            using (var fileNameBytes = reader.ReadScope(nameSize))
             {
-                case HeaderType.FileHeader:
+                switch (HeaderType)
                 {
-                    if (FileFlags.HasFlag(FileFlags.UNICODE))
+                    case HeaderType.FileHeader:
                     {
-                        int length = 0;
-                        while (length < fileNameBytes.Length
-                               && fileNameBytes[length] != 0)
+                        if (FileFlags.HasFlag(FileFlags.UNICODE))
                         {
-                            length++;
-                        }
-                        if (length != nameSize)
-                        {
-                            length++;
-                            FileName = FileNameDecoder.Decode(fileNameBytes, length);
+                            int length = 0;
+                            while (length < fileNameBytes.Count
+                                   && fileNameBytes[length] != 0)
+                            {
+                                length++;
+                            }
+                            if (length != nameSize)
+                            {
+                                length++;
+                                FileName = FileNameDecoder.Decode(fileNameBytes, length);
+                            }
+                            else
+                            {
+                                FileName = DecodeDefault(fileNameBytes);
+                            }
                         }
                         else
                         {
                             FileName = DecodeDefault(fileNameBytes);
                         }
+                        FileName = ConvertPath(FileName, HostOS);
                     }
-                    else
+                        break;
+                    case HeaderType.NewSubHeader:
                     {
-                        FileName = DecodeDefault(fileNameBytes);
-                    }
-                    FileName = ConvertPath(FileName, HostOS);
-                }
-                    break;
-                case HeaderType.NewSubHeader:
-                {
-                    int datasize = HeaderSize - NEWLHD_SIZE - nameSize;
-                    if (FileFlags.HasFlag(FileFlags.SALT))
-                    {
-                        datasize -= SALT_SIZE;
-                    }
-                    if (datasize > 0)
-                    {
-                        SubData = reader.ReadBytes(datasize);
-                    }
+                        int datasize = HeaderSize - NEWLHD_SIZE - nameSize;
+                        if (FileFlags.HasFlag(FileFlags.SALT))
+                        {
+                            datasize -= SALT_SIZE;
+                        }
+                        if (datasize > 0)
+                        {
+                            SubData = reader.ReadBytes(datasize);
+                        }
 
-                    if (NewSubHeaderType.SUBHEAD_TYPE_RR.Equals(fileNameBytes))
-                    {
-                        RecoverySectors = SubData[8] + (SubData[9] << 8)
-                                          + (SubData[10] << 16) + (SubData[11] << 24);
+                        if (NewSubHeaderType.SUBHEAD_TYPE_RR.Equals(fileNameBytes))
+                        {
+                            RecoverySectors = SubData[8] + (SubData[9] << 8)
+                                              + (SubData[10] << 16) + (SubData[11] << 24);
+                        }
                     }
+                        break;
                 }
-                    break;
-            }
 
-            if (FileFlags.HasFlag(FileFlags.SALT))
-            {
-                Salt = reader.ReadBytes(SALT_SIZE);
-            }
-            if (FileFlags.HasFlag(FileFlags.EXTTIME))
-            {
-                // verify that the end of the header hasn't been reached before reading the Extended Time.
-                //  some tools incorrectly omit Extended Time despite specifying FileFlags.EXTTIME, which most parsers tolerate.
-                if (ReadBytes + reader.CurrentReadByteCount <= HeaderSize - 2)
+                if (FileFlags.HasFlag(FileFlags.SALT))
                 {
-                    ushort extendedFlags = reader.ReadUInt16();
-                    FileLastModifiedTime = ProcessExtendedTime(extendedFlags, FileLastModifiedTime, reader, 0);
-                    FileCreatedTime = ProcessExtendedTime(extendedFlags, null, reader, 1);
-                    FileLastAccessedTime = ProcessExtendedTime(extendedFlags, null, reader, 2);
-                    FileArchivedTime = ProcessExtendedTime(extendedFlags, null, reader, 3);
+                    Salt = reader.ReadBytes(SALT_SIZE);
+                }
+                if (FileFlags.HasFlag(FileFlags.EXTTIME))
+                {
+                    // verify that the end of the header hasn't been reached before reading the Extended Time.
+                    //  some tools incorrectly omit Extended Time despite specifying FileFlags.EXTTIME, which most parsers tolerate.
+                    if (ReadBytes + reader.CurrentReadByteCount <= HeaderSize - 2)
+                    {
+                        ushort extendedFlags = reader.ReadUInt16();
+                        FileLastModifiedTime = ProcessExtendedTime(extendedFlags, FileLastModifiedTime, reader, 0);
+                        FileCreatedTime = ProcessExtendedTime(extendedFlags, null, reader, 1);
+                        FileLastAccessedTime = ProcessExtendedTime(extendedFlags, null, reader, 2);
+                        FileArchivedTime = ProcessExtendedTime(extendedFlags, null, reader, 3);
+                    }
                 }
             }
         }
 
         //only the full .net framework will do other code pages than unicode/utf8
-        private string DecodeDefault(byte[] bytes)
+        private string DecodeDefault(ByteArrayPoolScope bytes)
         {
-            return ArchiveEncoding.Default.GetString(bytes, 0, bytes.Length);
+            return ArchiveEncoding.Default.GetString(bytes.Array, 0, bytes.Count);
         }
 
         private long UInt32To64(uint x, uint y)

src/SharpCompress/Common/Rar/Headers/FileNameDecoder.cs

@@ -1,4 +1,5 @@
 using System.Text;
+using SharpCompress.IO;
 
 namespace SharpCompress.Common.Rar.Headers
 {
@@ -7,12 +8,12 @@ namespace SharpCompress.Common.Rar.Headers
     /// </summary>
     internal static class FileNameDecoder
     {
-        internal static int GetChar(byte[] name, int pos)
+        internal static int GetChar(ByteArrayPoolScope name, int pos)
         {
             return name[pos] & 0xff;
         }
 
-        internal static string Decode(byte[] name, int encPos)
+        internal static string Decode(ByteArrayPoolScope name, int encPos)
         {
             int decPos = 0;
             int flags = 0;
@@ -22,7 +23,7 @@ namespace SharpCompress.Common.Rar.Headers
             int high = 0;
             int highByte = GetChar(name, encPos++);
             StringBuilder buf = new StringBuilder();
-            while (encPos < name.Length)
+            while (encPos < name.Count)
             {
                 if (flagBits == 0)
                 {
@@ -54,7 +55,7 @@ namespace SharpCompress.Common.Rar.Headers
                         if ((length & 0x80) != 0)
                         {
                             int correction = GetChar(name, encPos++);
-                            for (length = (length & 0x7f) + 2; length > 0 && decPos < name.Length; length--, decPos++)
+                            for (length = (length & 0x7f) + 2; length > 0 && decPos < name.Count; length--, decPos++)
                             {
                                 low = (GetChar(name, decPos) + correction) & 0xff;
                                 buf.Append((char)((highByte << 8) + low));
@@ -62,7 +63,7 @@ namespace SharpCompress.Common.Rar.Headers
                         }
                         else
                         {
-                            for (length += 2; length > 0 && decPos < name.Length; length--, decPos++)
+                            for (length += 2; length > 0 && decPos < name.Count; length--, decPos++)
                             {
                                 buf.Append((char)(GetChar(name, decPos)));
                             }

src/SharpCompress/Common/Rar/Headers/RarHeader.cs

@@ -62,7 +62,8 @@ namespace SharpCompress.Common.Rar.Headers
 
             if (headerSizeDiff > 0)
             {
-                reader.ReadBytes(headerSizeDiff);
+                using (reader.ReadScope(headerSizeDiff))
+                { }
             }
 
             return header;

src/SharpCompress/Common/Rar/Headers/RarHeaderFactory.cs

@@ -52,35 +52,39 @@ namespace SharpCompress.Common.Rar.Headers
                     if (firstByte == 0x52)
                     {
                         MemoryStream buffer = new MemoryStream();
-                        byte[] nextThreeBytes = reader.ReadBytes(3);
-                        if ((nextThreeBytes[0] == 0x45)
-                            && (nextThreeBytes[1] == 0x7E)
-                            && (nextThreeBytes[2] == 0x5E))
+                        using (var nextThreeBytes = reader.ReadScope(3))
                         {
-                            //old format and isvalid
-                            buffer.WriteByte(0x52);
-                            buffer.Write(nextThreeBytes, 0, 3);
-                            rewindableStream.Rewind(buffer);
-                            break;
+                            if ((nextThreeBytes[0] == 0x45)
+                                && (nextThreeBytes[1] == 0x7E)
+                                && (nextThreeBytes[2] == 0x5E))
+                            {
+                                //old format and isvalid
+                                buffer.WriteByte(0x52);
+                                buffer.Write(nextThreeBytes.Array, 0, 3);
+                                rewindableStream.Rewind(buffer);
+                                break;
+                            }
+                            using (var secondThreeBytes = reader.ReadScope(3))
+                            {
+                                if ((nextThreeBytes[0] == 0x61)
+                                    && (nextThreeBytes[1] == 0x72)
+                                    && (nextThreeBytes[2] == 0x21)
+                                    && (secondThreeBytes[0] == 0x1A)
+                                    && (secondThreeBytes[1] == 0x07)
+                                    && (secondThreeBytes[2] == 0x00))
+                                {
+                                    //new format and isvalid
+                                    buffer.WriteByte(0x52);
+                                    buffer.Write(nextThreeBytes.Array, 0, 3);
+                                    buffer.Write(secondThreeBytes.Array, 0, 3);
+                                    rewindableStream.Rewind(buffer);
+                                    break;
+                                }
+                                buffer.Write(nextThreeBytes.Array, 0, 3);
+                                buffer.Write(secondThreeBytes.Array, 0, 3);
+                                rewindableStream.Rewind(buffer);
+                            }
                         }
-                        byte[] secondThreeBytes = reader.ReadBytes(3);
-                        if ((nextThreeBytes[0] == 0x61)
-                            && (nextThreeBytes[1] == 0x72)
-                            && (nextThreeBytes[2] == 0x21)
-                            && (secondThreeBytes[0] == 0x1A)
-                            && (secondThreeBytes[1] == 0x07)
-                            && (secondThreeBytes[2] == 0x00))
-                        {
-                            //new format and isvalid
-                            buffer.WriteByte(0x52);
-                            buffer.Write(nextThreeBytes, 0, 3);
-                            buffer.Write(secondThreeBytes, 0, 3);
-                            rewindableStream.Rewind(buffer);
-                            break;
-                        }
-                        buffer.Write(nextThreeBytes, 0, 3);
-                        buffer.Write(secondThreeBytes, 0, 3);
-                        rewindableStream.Rewind(buffer);
                     }
                     if (count > MAX_SFX_SIZE)
                     {

src/SharpCompress/Common/Rar/RarCryptoBinaryReader.cs

@@ -32,14 +32,21 @@ namespace SharpCompress.Common.Rar
 
         public override byte[] ReadBytes(int count)
         {
-            if (UseEncryption)
-            {
-                return ReadAndDecryptBytes(count);
-            }
-            return base.ReadBytes(count);
+            byte[] b = new byte[count];
+            Read(b, 0, count);
+            return b;
         }
 
-        private byte[] ReadAndDecryptBytes(int count)
+        public override int Read(byte[] buffer, int index, int count)
+        {
+            if (UseEncryption)
+            {
+                return ReadAndDecryptBytes(buffer, index, count);
+            }
+            return base.Read(buffer, index, count);
+        }
+
+        private int ReadAndDecryptBytes(byte[] buffer, int index, int count)
         {
             int queueSize = data.Count;
             int sizeToRead = count - queueSize;
@@ -49,23 +56,41 @@ namespace SharpCompress.Common.Rar
                 int alignedSize = sizeToRead + ((~sizeToRead + 1) & 0xf);
                 for (int i = 0; i < alignedSize / 16; i++)
                 {
-                    //long ax = System.currentTimeMillis();
-                    byte[] cipherText = base.ReadBytes(16);
-                    var readBytes = rijndael.ProcessBlock(cipherText);
-                    foreach (var readByte in readBytes)
-                        data.Enqueue(readByte);
-
+                    using (var cipherText = PrivateReadScope(16))
+                    {
+                        var readBytes = rijndael.ProcessBlock(cipherText);
+                        foreach (var readByte in readBytes)
+                        {
+                            data.Enqueue(readByte);
+                        }
+                    }
                 }
-
             }
-
-            var decryptedBytes = new byte[count];
-
-            for (int i = 0; i < count; i++)
+            
+            for (int i = index; i < count; i++)
             {
-                decryptedBytes[i] = data.Dequeue();
+                buffer[i] = data.Dequeue();
             }
-            return decryptedBytes;
+            return count;
+        }
+
+
+        private ByteArrayPoolScope PrivateReadScope(int count)
+        {
+            var scope = ByteArrayPool.RentScope(count);
+            int numRead = 0;
+            do
+            {
+                int n = base.Read(scope.Array, numRead, count);
+                if (n == 0)
+                {
+                    break;
+                }
+                numRead += n;
+                count -= n;
+            } while (count > 0);
+            scope.OverrideSize(numRead);
+            return scope;
         }
 
         public void ClearQueue()

src/SharpCompress/Common/Rar/RarCryptoWrapper.cs

@@ -3,6 +3,7 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using SharpCompress.IO;
 
 namespace SharpCompress.Common.Rar
 {
@@ -55,17 +56,21 @@ namespace SharpCompress.Common.Rar
                 for (int i = 0; i < alignedSize / 16; i++)
                 {
                     //long ax = System.currentTimeMillis();
-                    byte[] cipherText = new byte[RarRijndael.CRYPTO_BLOCK_SIZE];
-                    actualStream.Read(cipherText, 0, RarRijndael.CRYPTO_BLOCK_SIZE);
-
-                    var readBytes = rijndael.ProcessBlock(cipherText);
-                    foreach (var readByte in readBytes)
-                        data.Enqueue(readByte);
-
+                    using (var cipherText = ByteArrayPool.RentScope(RarRijndael.CRYPTO_BLOCK_SIZE))
+                    {
+                        actualStream.Read(cipherText.Array, 0, RarRijndael.CRYPTO_BLOCK_SIZE);
+                        var readBytes = rijndael.ProcessBlock(cipherText);
+                        foreach (var readByte in readBytes)
+                        {
+                            data.Enqueue(readByte);
+                        }
+                    }
                 }
 
                 for (int i = 0; i < count; i++)
+                {
                     buffer[offset + i] = data.Dequeue();
+                }
             }
             return count;
         }

src/SharpCompress/Common/Rar/RarRijndael.cs

@@ -6,6 +6,7 @@ using System.Security.Cryptography;
 using System.Text;
 using Org.BouncyCastle.Crypto.Engines;
 using Org.BouncyCastle.Crypto.Parameters;
+using SharpCompress.IO;
 
 namespace SharpCompress.Common.Rar
 {
@@ -96,22 +97,24 @@ namespace SharpCompress.Common.Rar
             return rijndael;
         }
 
-        public byte[] ProcessBlock(byte[] cipherText)
+        public byte[] ProcessBlock(ByteArrayPoolScope cipherText)
         {
-            var plainText = new byte[CRYPTO_BLOCK_SIZE];
-            var decryptedBytes = new List<byte>();
-            rijndael.ProcessBlock(cipherText, 0, plainText, 0);
-
-            for (int j = 0; j < plainText.Length; j++)
+            using (var plainText = ByteArrayPool.RentScope(CRYPTO_BLOCK_SIZE))
             {
-                decryptedBytes.Add((byte) (plainText[j] ^ aesInitializationVector[j%16])); //32:114, 33:101
-            }
+                var decryptedBytes = new List<byte>();
+                rijndael.ProcessBlock(cipherText, plainText);
 
-            for (int j = 0; j < aesInitializationVector.Length; j++)
-            {
-                aesInitializationVector[j] = cipherText[j];
+                for (int j = 0; j < plainText.Count; j++)
+                {
+                    decryptedBytes.Add((byte)(plainText[j] ^ aesInitializationVector[j % 16])); //32:114, 33:101
+                }
+
+                for (int j = 0; j < aesInitializationVector.Length; j++)
+                {
+                    aesInitializationVector[j] = cipherText[j];
+                }
+                return decryptedBytes.ToArray();
             }
-            return decryptedBytes.ToArray();
         }
 
         public void Dispose()

src/SharpCompress/Common/Tar/Headers/TarHeader.cs

@@ -2,6 +2,7 @@
 using System.IO;
 using System.Text;
 using SharpCompress.Converters;
+using SharpCompress.IO;
 
 namespace SharpCompress.Common.Tar.Headers
 {
@@ -87,63 +88,75 @@ namespace SharpCompress.Common.Tar.Headers
         internal bool Read(BinaryReader reader)
         {
             var buffer = ReadBlock(reader);
-            if (buffer.Length == 0)
+            try
             {
-                return false;
-            }
-
-            if (ReadEntryType(buffer) == EntryType.LongName)
-            {
-                Name = ReadLongName(reader, buffer);
-                buffer = ReadBlock(reader);
-            }
-            else
-            {
-                Name = ArchiveEncoding.Default.GetString(buffer, 0, 100).TrimNulls();
-            }
-
-            EntryType = ReadEntryType(buffer);
-            Size = ReadSize(buffer);
-
-            //Mode = ReadASCIIInt32Base8(buffer, 100, 7);
-            //UserId = ReadASCIIInt32Base8(buffer, 108, 7);
-            //GroupId = ReadASCIIInt32Base8(buffer, 116, 7);
-            long unixTimeStamp = ReadASCIIInt64Base8(buffer, 136, 11);
-            LastModifiedTime = Epoch.AddSeconds(unixTimeStamp).ToLocalTime();
-
-            Magic = ArchiveEncoding.Default.GetString(buffer, 257, 6).TrimNulls();
-
-            if (!string.IsNullOrEmpty(Magic)
-                && "ustar".Equals(Magic))
-            {
-                string namePrefix = ArchiveEncoding.Default.GetString(buffer, 345, 157);
-                namePrefix = namePrefix.TrimNulls();
-                if (!string.IsNullOrEmpty(namePrefix))
+                if (buffer.Count == 0)
                 {
-                    Name = namePrefix + "/" + Name;
+                    return false;
                 }
+
+                if (ReadEntryType(buffer.Array) == EntryType.LongName)
+                {
+                    Name = ReadLongName(reader, buffer.Array);
+                    buffer.Dispose();
+                    buffer = ReadBlock(reader);
+                }
+                else
+                {
+                    Name = ArchiveEncoding.Default.GetString(buffer.Array, 0, 100).TrimNulls();
+                }
+
+                EntryType = ReadEntryType(buffer.Array);
+                Size = ReadSize(buffer.Array);
+
+                //Mode = ReadASCIIInt32Base8(buffer, 100, 7);
+                //UserId = ReadASCIIInt32Base8(buffer, 108, 7);
+                //GroupId = ReadASCIIInt32Base8(buffer, 116, 7);
+                long unixTimeStamp = ReadASCIIInt64Base8(buffer.Array, 136, 11);
+                LastModifiedTime = Epoch.AddSeconds(unixTimeStamp).ToLocalTime();
+
+                Magic = ArchiveEncoding.Default.GetString(buffer.Array, 257, 6).TrimNulls();
+
+                if (!string.IsNullOrEmpty(Magic)
+                    && "ustar".Equals(Magic))
+                {
+                    string namePrefix = ArchiveEncoding.Default.GetString(buffer.Array, 345, 157);
+                    namePrefix = namePrefix.TrimNulls();
+                    if (!string.IsNullOrEmpty(namePrefix))
+                    {
+                        Name = namePrefix + "/" + Name;
+                    }
+                }
+                if (EntryType != EntryType.LongName
+                    && Name.Length == 0)
+                {
+                    return false;
+                }
+                return true;
             }
-            if (EntryType != EntryType.LongName
-                && Name.Length == 0)
+            finally
             {
-                return false;
+                buffer.Dispose();
             }
-            return true;
         }
 
         private string ReadLongName(BinaryReader reader, byte[] buffer)
         {
             var size = ReadSize(buffer);
             var nameLength = (int)size;
-            var nameBytes = reader.ReadBytes(nameLength);
-            var remainingBytesToRead = BlockSize - (nameLength % BlockSize);
-
-            // Read the rest of the block and discard the data
-            if (remainingBytesToRead < BlockSize)
+            using (var nameBytes = reader.ReadScope(nameLength))
             {
-                reader.ReadBytes(remainingBytesToRead);
+                var remainingBytesToRead = BlockSize - (nameLength % BlockSize);
+
+                // Read the rest of the block and discard the data
+                if (remainingBytesToRead < BlockSize)
+                {
+                    using (reader.ReadScope(remainingBytesToRead))
+                    {
+                    }
+                }
+                return ArchiveEncoding.Default.GetString(nameBytes.Array, 0, nameBytes.Count).TrimNulls();
             }
-            return ArchiveEncoding.Default.GetString(nameBytes, 0, nameBytes.Length).TrimNulls();
         }
 
         private static EntryType ReadEntryType(byte[] buffer)
@@ -160,11 +173,11 @@ namespace SharpCompress.Common.Tar.Headers
             return ReadASCIIInt64Base8(buffer, 124, 11);
         }
 
-        private static byte[] ReadBlock(BinaryReader reader)
+        private static ByteArrayPoolScope ReadBlock(BinaryReader reader)
         {
-            byte[] buffer = reader.ReadBytes(BlockSize);
+            var buffer = reader.ReadScope(BlockSize);
 
-            if (buffer.Length != 0 && buffer.Length < BlockSize)
+            if (buffer.Count != 0 && buffer.Count < BlockSize)
             {
                 throw new InvalidOperationException("Buffer is invalid size");
             }

src/SharpCompress/Common/Volume.cs

@@ -8,10 +8,10 @@ namespace SharpCompress.Common
     {
         private readonly Stream actualStream;
 
-        internal Volume(Stream stream, ReaderOptions readerFactoryOptions)
+        internal Volume(Stream stream, ReaderOptions readerOptions)
         {
             actualStream = stream;
-            ReaderOptions = readerFactoryOptions;
+            ReaderOptions = readerOptions;
         }
 
         internal Stream Stream { get { return new NonDisposingStream(actualStream); } }

src/SharpCompress/Common/Zip/Headers/DirectoryEntryHeader.cs

@@ -1,5 +1,6 @@
 using System.IO;
 using System.Linq;
+using SharpCompress.IO;
 
 namespace SharpCompress.Common.Zip.Headers
 {
@@ -29,12 +30,16 @@ namespace SharpCompress.Common.Zip.Headers
             ExternalFileAttributes = reader.ReadUInt32();
             RelativeOffsetOfEntryHeader = reader.ReadUInt32();
 
-            byte[] name = reader.ReadBytes(nameLength);
-            Name = DecodeString(name);
-            byte[] extra = reader.ReadBytes(extraLength);
-            byte[] comment = reader.ReadBytes(commentLength);
-            Comment = DecodeString(comment);
-            LoadExtra(extra);
+            using (var name = reader.ReadScope(nameLength))
+            {
+                Name = DecodeString(name);
+            }
+            using (var extra = reader.ReadScope(extraLength))
+            using (var comment = reader.ReadScope(commentLength))
+            {
+                Comment = DecodeString(comment);
+                LoadExtra(extra);
+            }
 
             var unicodePathExtra = Extra.FirstOrDefault(u => u.Type == ExtraDataType.UnicodePathExtraField);
             if (unicodePathExtra != null)

src/SharpCompress/Common/Zip/Headers/LocalEntryHeader.cs

@@ -1,5 +1,6 @@
 using System.IO;
 using System.Linq;
+using SharpCompress.IO;
 
 namespace SharpCompress.Common.Zip.Headers
 {
@@ -22,10 +23,12 @@ namespace SharpCompress.Common.Zip.Headers
             UncompressedSize = reader.ReadUInt32();
             ushort nameLength = reader.ReadUInt16();
             ushort extraLength = reader.ReadUInt16();
-            byte[] name = reader.ReadBytes(nameLength);
-            byte[] extra = reader.ReadBytes(extraLength);
-            Name = DecodeString(name);
-            LoadExtra(extra);
+            using (var name = reader.ReadScope(nameLength))
+            using (var extra = reader.ReadScope(extraLength))
+            {
+                Name = DecodeString(name);
+                LoadExtra(extra);
+            }
 
             var unicodePathExtra = Extra.FirstOrDefault(u => u.Type == ExtraDataType.UnicodePathExtraField);
             if (unicodePathExtra != null)

src/SharpCompress/Common/Zip/Headers/ZipFileEntry.cs

@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.IO;
 using System.Text;
 using SharpCompress.Converters;
+using SharpCompress.IO;
 
 namespace SharpCompress.Common.Zip.Headers
 {
@@ -30,14 +31,14 @@ namespace SharpCompress.Common.Zip.Headers
             }
         }
 
-        protected string DecodeString(byte[] str)
+        protected string DecodeString(ByteArrayPoolScope str)
         {
             if (FlagUtility.HasFlag(Flags, HeaderFlags.UTF8))
             {
-                return Encoding.UTF8.GetString(str, 0, str.Length);
+                return Encoding.UTF8.GetString(str.Array, 0, str.Count);
             }
 
-            return ArchiveEncoding.Default.GetString(str, 0, str.Length);
+            return ArchiveEncoding.Default.GetString(str.Array, 0, str.Count);
         }
 
         protected byte[] EncodeString(string str)
@@ -76,20 +77,22 @@ namespace SharpCompress.Common.Zip.Headers
 
         internal uint Crc { get; set; }
 
-        protected void LoadExtra(byte[] extra)
+        protected void LoadExtra(ByteArrayPoolScope extra)
         {
-            for (int i = 0; i < extra.Length - 4;)
+            for (int i = 0; i < extra.Count - 4;)
             {
-                ExtraDataType type = (ExtraDataType)DataConverter.LittleEndian.GetUInt16(extra, i);
+                ExtraDataType type = (ExtraDataType)DataConverter.LittleEndian.GetUInt16(extra.Array, i);
                 if (!Enum.IsDefined(typeof(ExtraDataType), type))
                 {
                     type = ExtraDataType.NotImplementedExtraData;
                 }
 
-                ushort length = DataConverter.LittleEndian.GetUInt16(extra, i + 2);
-                byte[] data = new byte[length];
-                Buffer.BlockCopy(extra, i + 4, data, 0, length);
-                Extra.Add(LocalEntryHeaderExtraFactory.Create(type, length, data));
+                ushort length = DataConverter.LittleEndian.GetUInt16(extra.Array, i + 2);
+                using (var data = ByteArrayPool.RentScope(length))
+                {
+                    Buffer.BlockCopy(extra.Array, i + 4, data.Array, 0, length);
+                    Extra.Add(LocalEntryHeaderExtraFactory.Create(type, length, data.Array));
+                }
 
                 i += length + 4;
             }

src/SharpCompress/Compressors/BZip2/BZip2Stream.cs

@@ -1,4 +1,5 @@
 using System.IO;
+using SharpCompress.IO;
 
 namespace SharpCompress.Compressors.BZip2
 {
@@ -91,12 +92,14 @@ namespace SharpCompress.Compressors.BZip2
         public static bool IsBZip2(Stream stream)
         {
             BinaryReader br = new BinaryReader(stream);
-            byte[] chars = br.ReadBytes(2);
-            if (chars.Length < 2 || chars[0] != 'B' || chars[1] != 'Z')
+            using (var chars = br.ReadScope(2))
             {
-                return false;
+                if (chars.Count < 2 || chars[0] != 'B' || chars[1] != 'Z')
+                {
+                    return false;
+                }
+                return true;
             }
-            return true;
         }
     }
 }

src/SharpCompress/Compressors/Deflate/GZipStream.cs

@@ -30,6 +30,7 @@ using System;
 using System.IO;
 using SharpCompress.Common;
 using SharpCompress.Converters;
+using SharpCompress.IO;
 
 namespace SharpCompress.Compressors.Deflate
 {
@@ -413,67 +414,74 @@ namespace SharpCompress.Compressors.Deflate
             int fnLength = (FileName == null) ? 0 : filenameBytes.Length + 1;
 
             int bufferLength = 10 + cbLength + fnLength;
-            var header = new byte[bufferLength];
-            int i = 0;
-
-            // ID
-            header[i++] = 0x1F;
-            header[i++] = 0x8B;
-
-            // compression method
-            header[i++] = 8;
-            byte flag = 0;
-            if (Comment != null)
+            var header = ByteArrayPool.RentWritable(bufferLength);
+            try
             {
-                flag ^= 0x10;
+                int i = 0;
+
+                // ID
+                header[i++] = 0x1F;
+                header[i++] = 0x8B;
+
+                // compression method
+                header[i++] = 8;
+                byte flag = 0;
+                if (Comment != null)
+                {
+                    flag ^= 0x10;
+                }
+                if (FileName != null)
+                {
+                    flag ^= 0x8;
+                }
+
+                // flag
+                header[i++] = flag;
+
+                // mtime
+                if (!LastModified.HasValue)
+                {
+                    LastModified = DateTime.Now;
+                }
+                TimeSpan delta = LastModified.Value - UnixEpoch;
+                var timet = (Int32)delta.TotalSeconds;
+                DataConverter.LittleEndian.PutBytes(header, i, timet);
+                i += 4;
+
+                // xflg
+                header[i++] = 0; // this field is totally useless
+
+                // OS
+                header[i++] = 0xFF; // 0xFF == unspecified
+
+                // extra field length - only if FEXTRA is set, which it is not.
+                //header[i++]= 0;
+                //header[i++]= 0;
+
+                // filename
+                if (fnLength != 0)
+                {
+                    Array.Copy(filenameBytes, 0, header, i, fnLength - 1);
+                    i += fnLength - 1;
+                    header[i++] = 0; // terminate
+                }
+
+                // comment
+                if (cbLength != 0)
+                {
+                    Array.Copy(commentBytes, 0, header, i, cbLength - 1);
+                    i += cbLength - 1;
+                    header[i++] = 0; // terminate
+                }
+
+                BaseStream._stream.Write(header, 0, bufferLength);
+
+                return bufferLength; // bytes written
             }
-            if (FileName != null)
+            finally
             {
-                flag ^= 0x8;
+                ByteArrayPool.Return(header);
             }
-
-            // flag
-            header[i++] = flag;
-
-            // mtime
-            if (!LastModified.HasValue)
-            {
-                LastModified = DateTime.Now;
-            }
-            TimeSpan delta = LastModified.Value - UnixEpoch;
-            var timet = (Int32)delta.TotalSeconds;
-            DataConverter.LittleEndian.PutBytes(header, i, timet);
-            i += 4;
-
-            // xflg
-            header[i++] = 0; // this field is totally useless
-
-            // OS
-            header[i++] = 0xFF; // 0xFF == unspecified
-
-            // extra field length - only if FEXTRA is set, which it is not.
-            //header[i++]= 0;
-            //header[i++]= 0;
-
-            // filename
-            if (fnLength != 0)
-            {
-                Array.Copy(filenameBytes, 0, header, i, fnLength - 1);
-                i += fnLength - 1;
-                header[i++] = 0; // terminate
-            }
-
-            // comment
-            if (cbLength != 0)
-            {
-                Array.Copy(commentBytes, 0, header, i, cbLength - 1);
-                i += cbLength - 1;
-                header[i++] = 0; // terminate
-            }
-
-            BaseStream._stream.Write(header, 0, header.Length);
-
-            return header.Length; // bytes written
         }
     }
 }

src/SharpCompress/Compressors/Deflate/ZlibBaseStream.cs

@@ -30,6 +30,7 @@ using System.IO;
 using SharpCompress.Common;
 using SharpCompress.Common.Tar.Headers;
 using SharpCompress.Converters;
+using SharpCompress.IO;
 
 namespace SharpCompress.Compressors.Deflate
 {
@@ -267,46 +268,48 @@ namespace SharpCompress.Compressors.Deflate
                         }
 
                         // Read and potentially verify the GZIP trailer: CRC32 and  size mod 2^32
-                        byte[] trailer = new byte[8];
-
-                        // workitem 8679
-                        if (_z.AvailableBytesIn != 8)
+                        using (var trailer = ByteArrayPool.RentScope(8))
                         {
-                            // Make sure we have read to the end of the stream
-                            Array.Copy(_z.InputBuffer, _z.NextIn, trailer, 0, _z.AvailableBytesIn);
-                            int bytesNeeded = 8 - _z.AvailableBytesIn;
-                            int bytesRead = _stream.Read(trailer,
-                                                         _z.AvailableBytesIn,
-                                                         bytesNeeded);
-                            if (bytesNeeded != bytesRead)
+
+                            // workitem 8679
+                            if (_z.AvailableBytesIn != 8)
                             {
-                                throw new ZlibException(String.Format(
-                                                                      "Protocol error. AvailableBytesIn={0}, expected 8",
-                                                                      _z.AvailableBytesIn + bytesRead));
+                                // Make sure we have read to the end of the stream
+                                Array.Copy(_z.InputBuffer, _z.NextIn, trailer.Array, 0, _z.AvailableBytesIn);
+                                int bytesNeeded = 8 - _z.AvailableBytesIn;
+                                int bytesRead = _stream.Read(trailer.Array,
+                                                             _z.AvailableBytesIn,
+                                                             bytesNeeded);
+                                if (bytesNeeded != bytesRead)
+                                {
+                                    throw new ZlibException(String.Format(
+                                                                          "Protocol error. AvailableBytesIn={0}, expected 8",
+                                                                          _z.AvailableBytesIn + bytesRead));
+                                }
+                            }
+                            else
+                            {
+                                Array.Copy(_z.InputBuffer, _z.NextIn, trailer.Array, 0, trailer.Count);
                             }
-                        }
-                        else
-                        {
-                            Array.Copy(_z.InputBuffer, _z.NextIn, trailer, 0, trailer.Length);
-                        }
 
-                        Int32 crc32_expected = DataConverter.LittleEndian.GetInt32(trailer, 0);
-                        Int32 crc32_actual = crc.Crc32Result;
-                        Int32 isize_expected = DataConverter.LittleEndian.GetInt32(trailer, 4);
-                        Int32 isize_actual = (Int32)(_z.TotalBytesOut & 0x00000000FFFFFFFF);
+                            Int32 crc32_expected = DataConverter.LittleEndian.GetInt32(trailer.Array, 0);
+                            Int32 crc32_actual = crc.Crc32Result;
+                            Int32 isize_expected = DataConverter.LittleEndian.GetInt32(trailer.Array, 4);
+                            Int32 isize_actual = (Int32)(_z.TotalBytesOut & 0x00000000FFFFFFFF);
 
-                        if (crc32_actual != crc32_expected)
-                        {
-                            throw new ZlibException(
-                                                    String.Format("Bad CRC32 in GZIP stream. (actual({0:X8})!=expected({1:X8}))",
-                                                                  crc32_actual, crc32_expected));
-                        }
+                            if (crc32_actual != crc32_expected)
+                            {
+                                throw new ZlibException(
+                                                        String.Format("Bad CRC32 in GZIP stream. (actual({0:X8})!=expected({1:X8}))",
+                                                                      crc32_actual, crc32_expected));
+                            }
 
-                        if (isize_actual != isize_expected)
-                        {
-                            throw new ZlibException(
-                                                    String.Format("Bad size in GZIP stream. (actual({0})!=expected({1}))", isize_actual,
-                                                                  isize_expected));
+                            if (isize_actual != isize_expected)
+                            {
+                                throw new ZlibException(
+                                                        String.Format("Bad size in GZIP stream. (actual({0})!=expected({1}))", isize_actual,
+                                                                      isize_expected));
+                            }
                         }
                     }
                     else
@@ -427,57 +430,61 @@ namespace SharpCompress.Compressors.Deflate
             int totalBytesRead = 0;
 
             // read the header on the first read
-            byte[] header = new byte[10];
-            int n = _stream.Read(header, 0, header.Length);
-
-            // workitem 8501: handle edge case (decompress empty stream)
-            if (n == 0)
+            using (var header = ByteArrayPool.RentScope(10))
             {
-                return 0;
-            }
+                int n = _stream.Read(header);
 
-            if (n != 10)
-            {
-                throw new ZlibException("Not a valid GZIP stream.");
-            }
-
-            if (header[0] != 0x1F || header[1] != 0x8B || header[2] != 8)
-            {
-                throw new ZlibException("Bad GZIP header.");
-            }
-
-            Int32 timet = DataConverter.LittleEndian.GetInt32(header, 4);
-            _GzipMtime = TarHeader.Epoch.AddSeconds(timet);
-            totalBytesRead += n;
-            if ((header[3] & 0x04) == 0x04)
-            {
-                // read and discard extra field
-                n = _stream.Read(header, 0, 2); // 2-byte length field
-                totalBytesRead += n;
-
-                Int16 extraLength = (Int16)(header[0] + header[1] * 256);
-                byte[] extra = new byte[extraLength];
-                n = _stream.Read(extra, 0, extra.Length);
-                if (n != extraLength)
+                // workitem 8501: handle edge case (decompress empty stream)
+                if (n == 0)
                 {
-                    throw new ZlibException("Unexpected end-of-file reading GZIP header.");
+                    return 0;
                 }
-                totalBytesRead += n;
-            }
-            if ((header[3] & 0x08) == 0x08)
-            {
-                _GzipFileName = ReadZeroTerminatedString();
-            }
-            if ((header[3] & 0x10) == 0x010)
-            {
-                _GzipComment = ReadZeroTerminatedString();
-            }
-            if ((header[3] & 0x02) == 0x02)
-            {
-                Read(_buf1, 0, 1); // CRC16, ignore
-            }
 
-            return totalBytesRead;
+                if (n != 10)
+                {
+                    throw new ZlibException("Not a valid GZIP stream.");
+                }
+
+                if (header[0] != 0x1F || header[1] != 0x8B || header[2] != 8)
+                {
+                    throw new ZlibException("Bad GZIP header.");
+                }
+
+                Int32 timet = DataConverter.LittleEndian.GetInt32(header.Array, 4);
+                _GzipMtime = TarHeader.Epoch.AddSeconds(timet);
+                totalBytesRead += n;
+                if ((header[3] & 0x04) == 0x04)
+                {
+                    // read and discard extra field
+                    n = _stream.Read(header.Array, 0, 2); // 2-byte length field
+                    totalBytesRead += n;
+
+                    Int16 extraLength = (Int16)(header[0] + header[1] * 256);
+                    using (var extra = ByteArrayPool.RentScope(extraLength))
+                    {
+                        n = _stream.Read(extra);
+                        if (n != extraLength)
+                        {
+                            throw new ZlibException("Unexpected end-of-file reading GZIP header.");
+                        }
+                        totalBytesRead += n;
+                    }
+                }
+                if ((header[3] & 0x08) == 0x08)
+                {
+                    _GzipFileName = ReadZeroTerminatedString();
+                }
+                if ((header[3] & 0x10) == 0x010)
+                {
+                    _GzipComment = ReadZeroTerminatedString();
+                }
+                if ((header[3] & 0x02) == 0x02)
+                {
+                    Read(_buf1, 0, 1); // CRC16, ignore
+                }
+
+                return totalBytesRead;
+            }
         }
 
         public override Int32 Read(Byte[] buffer, Int32 offset, Int32 count)

src/SharpCompress/Compressors/PPMd/PpmdProperties.cs

@@ -3,13 +3,6 @@ using SharpCompress.Converters;
 
 namespace SharpCompress.Compressors.PPMd
 {
-    public enum PpmdVersion
-    {
-        H,
-        H7z,
-        I1
-    }
-
     public class PpmdProperties
     {
         public PpmdVersion Version = PpmdVersion.I1;

src/SharpCompress/Compressors/PPMd/PpmdVersion.cs

@@ -0,0 +1,9 @@
+namespace SharpCompress.Compressors.PPMd
+{
+    public enum PpmdVersion
+    {
+        H,
+        H7z,
+        I1
+    }
+}

src/SharpCompress/Crypto/IBlockCipher.cs

@@ -1,4 +1,6 @@
-namespace Org.BouncyCastle.Crypto
+using SharpCompress.IO;
+
+namespace Org.BouncyCastle.Crypto
 {
     /// <remarks>Base interface for a symmetric key block cipher.</remarks>
     public interface IBlockCipher
@@ -18,13 +20,11 @@
         bool IsPartialBlockOkay { get; }
 
         /// <summary>Process a block.</summary>
-        /// <param name="inBuf">The input buffer.</param>
-        /// <param name="inOff">The offset into <paramref>inBuf</paramref> that the input block begins.</param>
-        /// <param name="outBuf">The output buffer.</param>
-        /// <param name="outOff">The offset into <paramref>outBuf</paramref> to write the output block.</param>
+        /// <param name="input">The input buffer.</param>
+        /// <param name="output">The output buffer.</param>
         /// <exception cref="DataLengthException">If input block is wrong size, or outBuf too small.</exception>
         /// <returns>The number of bytes processed and produced.</returns>
-        int ProcessBlock(byte[] inBuf, int inOff, byte[] outBuf, int outOff);
+        int ProcessBlock(ByteArrayPoolScope input, ByteArrayPoolScope output);
 
         /// <summary>
         /// Reset the cipher to the same state as it was after the last init (if there was one).

src/SharpCompress/Crypto/RijndaelEngine.cs

@@ -1,5 +1,6 @@
 using System;
 using Org.BouncyCastle.Crypto.Parameters;
+using SharpCompress.IO;
 
 namespace Org.BouncyCastle.Crypto.Engines
 {
@@ -586,28 +587,24 @@ namespace Org.BouncyCastle.Crypto.Engines
             return BC / 2;
         }
 
-        public int ProcessBlock(
-            byte[] input,
-            int inOff,
-            byte[] output,
-            int outOff)
+        public int ProcessBlock(ByteArrayPoolScope input, ByteArrayPoolScope output)
         {
             if (workingKey == null)
             {
                 throw new InvalidOperationException("Rijndael engine not initialised");
             }
 
-            if ((inOff + (BC / 2)) > input.Length)
+            if ((input.Offset + (BC / 2)) > input.Count)
             {
                 throw new DataLengthException("input buffer too short");
             }
 
-            if ((outOff + (BC / 2)) > output.Length)
+            if ((output.Offset + (BC / 2)) > output.Count)
             {
                 throw new DataLengthException("output buffer too short");
             }
 
-            UnPackBlock(input, inOff);
+            UnPackBlock(input.Array, input.Offset);
 
             if (forEncryption)
             {
@@ -618,7 +615,7 @@ namespace Org.BouncyCastle.Crypto.Engines
                 DecryptBlock(workingKey);
             }
 
-            PackBlock(output, outOff);
+            PackBlock(output.Array, output.Offset);
 
             return BC / 2;
         }

src/SharpCompress/IO/ByteArrayPool.cs

@@ -0,0 +1,52 @@
+using System;
+#if !NO_BUFFERS
+using System.Buffers;
+#endif
+
+namespace SharpCompress.IO
+{
+    public static class ByteArrayPool
+    {
+#if !NO_BUFFERS
+        private static readonly ArrayPool<byte> POOL = ArrayPool<byte>.Create();
+#endif
+        public static ArraySegment<byte> Rent(int size)
+        {
+#if NO_BUFFERS
+            return new ArraySegment<byte>(new byte[size]);
+#else
+            return new ArraySegment<byte>(POOL.Rent(size), 0, size);
+#endif
+        }
+
+        public static byte[] RentWritable(int size)
+        {
+#if NO_BUFFERS
+            return new byte[size];
+#else
+            return POOL.Rent(size);
+#endif
+        }
+
+        public static ByteArrayPoolScope RentScope(int size)
+        {
+            return new ByteArrayPoolScope(Rent(size));
+        }
+
+
+        public static void Return(ArraySegment<byte> array)
+        {
+#if NO_BUFFERS
+#else
+            POOL.Return(array.Array);
+#endif
+        }
+        public static void Return(byte[] array)
+        {
+#if NO_BUFFERS
+#else
+            POOL.Return(array);
+#endif
+        }
+    }
+}

src/SharpCompress/IO/ByteArrayPoolScope.cs

@@ -0,0 +1,35 @@
+using System;
+
+namespace SharpCompress.IO
+{
+    public struct ByteArrayPoolScope : IDisposable
+    {
+        private readonly ArraySegment<byte> array;
+        private int? overridenSize;
+        public ByteArrayPoolScope(ArraySegment<byte> array)
+        {
+            this.array = array;
+            overridenSize = null;
+        }
+
+        public byte[] Array => array.Array;
+        public int Offset => array.Offset;
+        public int Count => overridenSize ?? array.Count;
+
+        public byte this[int index]
+        {
+            get { return Array[index]; }
+            set { Array[index] = value; }
+        }
+
+        public void Dispose()
+        {
+            ByteArrayPool.Return(array);
+        }
+
+        public void OverrideSize(int newSize)
+        {
+            overridenSize = newSize;
+        }
+    }
+}

src/SharpCompress/IO/ByteArrayPoolScopeExtensions.cs

@@ -0,0 +1,30 @@
+using System.IO;
+
+namespace SharpCompress.IO
+{
+    public static class ByteArrayPoolScopeExtensions
+    {
+        public static int Read(this Stream stream, ByteArrayPoolScope scope)
+        {
+            return stream.Read(scope.Array, scope.Offset, scope.Count);
+        }
+
+        public static ByteArrayPoolScope ReadScope(this BinaryReader stream, int count)
+        {
+            var scope = ByteArrayPool.RentScope(count);
+            int numRead = 0;
+            do
+            {
+                int n = stream.Read(scope.Array, numRead, count);
+                if (n == 0)
+                {
+                    break;
+                }
+                numRead += n;
+                count -= n;
+            } while (count > 0);
+            scope.OverrideSize(numRead);
+            return scope;
+        }
+    }
+}

src/SharpCompress/IO/MarkingBinaryReader.cs

@@ -26,7 +26,9 @@ namespace SharpCompress.IO
 
         public override int Read(byte[] buffer, int index, int count)
         {
-            throw new NotSupportedException();
+            int read = base.Read(buffer, index, count);
+            CurrentReadByteCount += read;
+            return read;
         }
 
         public override int Read(char[] buffer, int index, int count)
@@ -36,12 +38,18 @@ namespace SharpCompress.IO
 
         public override bool ReadBoolean()
         {
-            return ReadBytes(1).Single() != 0;
+            using (var b = this.ReadScope(1))
+            {
+                return b.Array.First() != 0;
+            }
         }
 
         public override byte ReadByte()
         {
-            return ReadBytes(1).Single();
+            using (var b = this.ReadScope(1))
+            {
+                return b.Array.First();
+            }
         }
 
         public override byte[] ReadBytes(int count)
@@ -79,17 +87,26 @@ namespace SharpCompress.IO
 
         public override short ReadInt16()
         {
-            return DataConverter.LittleEndian.GetInt16(ReadBytes(2), 0);
+            using (var b = this.ReadScope(2))
+            {
+                return DataConverter.LittleEndian.GetInt16(b.Array, 0);
+            }
         }
 
         public override int ReadInt32()
         {
-            return DataConverter.LittleEndian.GetInt32(ReadBytes(4), 0);
+            using (var b = this.ReadScope(4))
+            {
+                return DataConverter.LittleEndian.GetInt32(b.Array, 0);
+            }
         }
 
         public override long ReadInt64()
         {
-            return DataConverter.LittleEndian.GetInt64(ReadBytes(8), 0);
+            using (var b = this.ReadScope(8))
+            {
+                return DataConverter.LittleEndian.GetInt64(b.Array, 0);
+            }
         }
 
         public override sbyte ReadSByte()
@@ -109,17 +126,26 @@ namespace SharpCompress.IO
 
         public override ushort ReadUInt16()
         {
-            return DataConverter.LittleEndian.GetUInt16(ReadBytes(2), 0);
+            using (var b = this.ReadScope(2))
+            {
+                return DataConverter.LittleEndian.GetUInt16(b.Array, 0);
+            }
         }
 
         public override uint ReadUInt32()
         {
-            return DataConverter.LittleEndian.GetUInt32(ReadBytes(4), 0);
+            using (var b = this.ReadScope(4))
+            {
+                return DataConverter.LittleEndian.GetUInt32(b.Array, 0);
+            }
         }
 
         public override ulong ReadUInt64()
         {
-            return DataConverter.LittleEndian.GetUInt64(ReadBytes(8), 0);
+            using (var b = this.ReadScope(8))
+            {
+                return DataConverter.LittleEndian.GetUInt64(b.Array, 0);
+            }
         }
     }
 }

src/SharpCompress/Readers/AbstractReader.cs

@@ -29,7 +29,7 @@ namespace SharpCompress.Readers
             Options = options;
         }
 
-        internal ReaderOptions Options { get; private set; }
+        internal ReaderOptions Options { get; }
 
         public ArchiveType ArchiveType { get; }
 

src/SharpCompress/Readers/ReaderFactory.cs

@@ -33,7 +33,7 @@ namespace SharpCompress.Readers
                                  };
             RewindableStream rewindableStream = new RewindableStream(stream);
             rewindableStream.StartRecording();
-            if (ZipArchive.IsZipFile(rewindableStream, null))
+            if (ZipArchive.IsZipFile(rewindableStream, options.Password))
             {
                 rewindableStream.Rewind(true);
                 return ZipReader.Open(rewindableStream, options);

src/SharpCompress/Utility.cs

@@ -2,6 +2,7 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using SharpCompress.IO;
 
 namespace SharpCompress
 {
@@ -137,37 +138,41 @@ namespace SharpCompress
 
         public static void Skip(this Stream source, long advanceAmount)
         {
-            byte[] buffer = new byte[32 * 1024];
-            int read = 0;
-            int readCount = 0;
-            do
+            using (var buffer = ByteArrayPool.RentScope(32 * 1024))
             {
-                readCount = buffer.Length;
-                if (readCount > advanceAmount)
+                int read = 0;
+                int readCount = 0;
+                do
                 {
-                    readCount = (int)advanceAmount;
-                }
-                read = source.Read(buffer, 0, readCount);
-                if (read <= 0)
-                {
-                    break;
-                }
-                advanceAmount -= read;
-                if (advanceAmount == 0)
-                {
-                    break;
+                    readCount = buffer.Count;
+                    if (readCount > advanceAmount)
+                    {
+                        readCount = (int)advanceAmount;
+                    }
+                    read = source.Read(buffer.Array, 0, readCount);
+                    if (read <= 0)
+                    {
+                        break;
+                    }
+                    advanceAmount -= read;
+                    if (advanceAmount == 0)
+                    {
+                        break;
+                    }
                 }
+                while (true);
             }
-            while (true);
         }
 
         public static void SkipAll(this Stream source)
         {
-            byte[] buffer = new byte[32 * 1024];
-            do
+            using (var buffer = ByteArrayPool.RentScope(32 * 1024))
             {
+                do
+                {
+                }
+                while (source.Read(buffer) > 0);
             }
-            while (source.Read(buffer, 0, buffer.Length) == buffer.Length);
         }
 
         public static DateTime DosDateToDateTime(UInt16 iDate, UInt16 iTime)
@@ -231,15 +236,17 @@ namespace SharpCompress
 
         public static long TransferTo(this Stream source, Stream destination)
         {
-            byte[] array = new byte[81920];
-            int count;
-            long total = 0;
-            while ((count = source.Read(array, 0, array.Length)) != 0)
+            using (var array = ByteArrayPool.RentScope(81920))
             {
-                total += count;
-                destination.Write(array, 0, count);
+                int count;
+                long total = 0;
+                while ((count = source.Read(array.Array, 0, array.Count)) != 0)
+                {
+                    total += count;
+                    destination.Write(array.Array, 0, count);
+                }
+                return total;
             }
-            return total;
         }
 
         public static bool ReadFully(this Stream stream, byte[] buffer)
@@ -261,14 +268,14 @@ namespace SharpCompress
         {
             return source.Replace('\0', ' ').Trim();
         }
-
-        public static bool BinaryEquals(this byte[] source, byte[] target)
+        
+        public static bool BinaryEquals(this ByteArrayPoolScope source, byte[] target)
         {
-            if (source.Length != target.Length)
+            if (source.Count != target.Length)
             {
                 return false;
             }
-            for (int i = 0; i < source.Length; ++i)
+            for (int i = 0; i < source.Count; ++i)
             {
                 if (source[i] != target[i])
                 {
@@ -277,10 +284,5 @@ namespace SharpCompress
             }
             return true;
         }
-
-        public static void CopyTo(this byte[] array, byte[] destination, int index)
-        {
-            Array.Copy(array, 0, destination, index, array.Length);
-        }
     }
 }

src/SharpCompress/Writers/Zip/ZipWriter.cs

@@ -19,10 +19,10 @@ namespace SharpCompress.Writers.Zip
     {
         private readonly CompressionType compressionType;
         private readonly CompressionLevel compressionLevel;
-        private readonly PpmdProperties ppmdProperties = new PpmdProperties(); // Caching properties to speed up PPMd
         private readonly List<ZipCentralDirectoryEntry> entries = new List<ZipCentralDirectoryEntry>();
         private readonly string zipComment;
         private long streamPosition;
+        private PpmdProperties ppmdProps;
 
         public ZipWriter(Stream destination, ZipWriterOptions zipWriterOptions)
             : base(ArchiveType.Zip)
@@ -34,6 +34,18 @@ namespace SharpCompress.Writers.Zip
             InitalizeStream(destination, !zipWriterOptions.LeaveStreamOpen);
         }
 
+        private PpmdProperties PpmdProperties
+        {
+            get
+            {
+                if (ppmdProps == null)
+                {
+                    ppmdProps = new PpmdProperties();
+                }
+                return ppmdProps;
+            }
+        }
+
         protected override void Dispose(bool isDisposing)
         {
             if (isDisposing)
@@ -252,8 +264,8 @@ namespace SharpCompress.Writers.Zip
                     }
                     case ZipCompressionMethod.PPMd:
                     {
-                        counting.Write(writer.ppmdProperties.Properties, 0, 2);
-                        return new PpmdStream(writer.ppmdProperties, counting, true);
+                        counting.Write(writer.PpmdProperties.Properties, 0, 2);
+                        return new PpmdStream(writer.PpmdProperties, counting, true);
                     }
                     default:
                     {

src/SharpCompress/project.json

@@ -1,5 +1,5 @@
 {
-    "version": "0.13.0",
+    "version": "0.13.1",
     "title": "SharpCompress - Pure C# Decompression/Compression",
     "authors": [ "Adam Hathcock" ],
     "language": "en-US",
@@ -16,15 +16,22 @@
         "allowUnsafe": true
     },
     "frameworks": {
-        "net35": {
-        },
         "net40": {
+            "buildOptions": {
+                "define": [ "NO_BUFFERS" ]
+            }
         },
         "net45": {
+            "dependencies": {
+                "System.Buffers": "4.0.0"
+            },
+            "frameworkAssemblies": {
+                "System.Runtime": { "type": "build" }
+            }
         },
         ".NETPortable,Version=v4.0,Profile=Profile328": {
             "buildOptions": {
-                "define": [ "NO_FILE", "NO_CRYPTO", "SILVERLIGHT" ]
+                "define": [ "NO_FILE", "NO_CRYPTO", "SILVERLIGHT", "NO_BUFFERS" ]
             },
             "frameworkAssemblies": {
                 "mscorlib": { "type": "build" },
@@ -34,7 +41,7 @@
         },
         ".NETPortable,Version=v4.5,Profile=Profile259": {
             "buildOptions": {
-                "define": [ "NO_FILE", "NO_CRYPTO", "SILVERLIGHT" ]
+                "define": [ "NO_FILE", "NO_CRYPTO", "SILVERLIGHT", "NO_BUFFERS" ]
             },
             "frameworkAssemblies": {
                 "System": { "type": "build" },
@@ -52,7 +59,7 @@
         },
         "netstandard1.0": {
             "buildOptions": {
-                "define": [ "NO_FILE", "NO_CRYPTO" ]
+                "define": [ "NO_FILE", "NO_CRYPTO", "NO_BUFFERS" ]
             },
             "dependencies": {
                 "System.Collections": "4.0.11",
@@ -64,8 +71,24 @@
                 "System.Text.Encoding.Extensions": "4.0.11"
             }
         },
+        "netstandard1.1": {
+            "buildOptions": {
+                "define": [ "NO_FILE", "NO_CRYPTO" ]
+            },
+            "dependencies": {
+                "System.Buffers": "4.0.0",
+                "System.Collections": "4.0.11",
+                "System.Diagnostics.Debug": "4.0.11",
+                "System.IO": "4.1.0",
+                "System.Linq": "4.1.0",
+                "System.Resources.ResourceManager": "4.0.1",
+                "System.Runtime.Extensions": "4.1.0",
+                "System.Text.Encoding.Extensions": "4.0.11"
+            }
+        },
         "netstandard1.3": {
             "dependencies": {
+                "System.Buffers": "4.0.0",
                 "System.Collections": "4.0.11",
                 "System.Diagnostics.Debug": "4.0.11",
                 "System.IO": "4.1.0",

test/SharpCompress.Test/Zip/ZipReaderTests.cs

@@ -228,6 +228,8 @@ namespace SharpCompress.Test
         [Fact]
         public void TestSharpCompressWithEmptyStream()
         {
+            ResetScratch();
+
             MemoryStream stream = new NonSeekableMemoryStream();
 
             using (IWriter zipWriter = WriterFactory.Open(stream, ArchiveType.Zip, CompressionType.Deflate))
@@ -250,7 +252,9 @@ namespace SharpCompress.Test
                         byte[] buf = new byte[bufSize];
                         int bytesRead = 0;
                         while ((bytesRead = entry.Read(buf, 0, bufSize)) > 0)
+                        {
                             tempStream.Write(buf, 0, bytesRead);
+                        }
                     }
                 }
             }

test/SharpCompress.Test/project.json

@@ -14,7 +14,7 @@
     "dependencies": {
         "Microsoft.Extensions.PlatformAbstractions": "1.0.0",
         "SharpCompress": { "target" : "project"},
-        "xunit": "2.2.0-beta2-build3300",
+        "xunit": "2.2.0-beta3-build3402",
         "dotnet-test-xunit": "2.2.0-preview2-build1029"
     }
 }