Add ARC methods 8 (Crunch) and 9 (squash), 12-bit and 13-bit Dynamic LZW.

CMakeLists.txt

@@ -142,7 +142,8 @@ add_library("Aaru.Compression.Native" SHARED library.c apple_rle.c apple_rle.h a
             zoo/maketbl.c
             arc/pack.c
             arc/squeeze.c
-            arc/crunch.c)
+            arc/crunch.c
+            arc/lzw.c)
 
 include(3rdparty/bzip2.cmake)
 include(3rdparty/flac.cmake)

arc/lzw.c

@@ -0,0 +1,270 @@
+/*
+ * This file is part of the Aaru Data Preservation Suite.
+ * Copyright (c) 2019-2025 Natalia Portillo.
+ * Copyright © 2018-2019 David Ryskalczyk
+ *
+ * This library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of the
+ * License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "../library.h"
+
+#define CRBITS     12                // Max bits for crunching.
+#define SQBITS     13                // Max bits for squashing.
+#define INIT_BITS  9                 // Initial number of bits per code.
+#define MAXCODE(n) ((1 << (n)) - 1)  // Macro to calculate max code for n bits.
+#define FIRST      257               // First available code.
+#define CLEAR      256               // Code to clear the dictionary.
+
+// LZW decompression state variables.
+static int             Bits;
+static int             max_maxcode;
+static int             n_bits;
+static int             maxcode;
+static int             clear_flg;
+static int             free_ent;
+static unsigned short *prefix;
+static unsigned char  *suffix;
+static unsigned char  *stack;
+
+// Buffer management variables.
+static const unsigned char *in_buf_ptr;
+static size_t               in_len_rem;
+static int                  offset;
+static char                 buf[SQBITS];
+
+// Reads a variable-length code from the input buffer.
+static int getcode()
+{
+    int            code;
+    static int     size = 0;
+    int            r_off, bits;
+    unsigned char *bp = (unsigned char *)buf;
+
+    // Check if we need to increase code size or handle a clear flag.
+    if(clear_flg > 0 || offset >= size || free_ent > maxcode)
+    {
+        if(free_ent > maxcode)
+        {
+            n_bits++;
+            if(n_bits == Bits)
+                maxcode = max_maxcode;
+            else
+                maxcode = MAXCODE(n_bits);
+        }
+        if(clear_flg > 0)
+        {
+            maxcode   = MAXCODE(n_bits = INIT_BITS);
+            clear_flg = 0;
+        }
+        // Read n_bits bytes into the buffer.
+        for(size = 0; size < n_bits; size++)
+        {
+            if(in_len_rem == 0)
+            {
+                code = -1;
+                break;
+            }
+            code = *in_buf_ptr++;
+            in_len_rem--;
+            buf[size] = (char)code;
+        }
+        if(size <= 0) return -1;  // End of file.
+
+        offset = 0;
+        size   = (size << 3) - (n_bits - 1);
+    }
+    r_off = offset;
+    bits  = n_bits;
+
+    // Extract the code from the buffer.
+    bp += (r_off >> 3);
+    r_off &= 7;
+
+    code = (*bp++ >> r_off);
+    bits -= 8 - r_off;
+    r_off = 8 - r_off;
+
+    if(bits >= 8)
+    {
+        code |= *bp++ << r_off;
+        r_off += 8;
+        bits -= 8;
+    }
+    code |= (*bp & ((1 << bits) - 1)) << r_off;
+    offset += n_bits;
+
+    return code;
+}
+
+// Main LZW decompression logic.
+static int arc_decompress_lzw(const unsigned char *in_buf, size_t in_len, unsigned char *out_buf, size_t *out_len,
+                              int squash)
+{
+    // Basic validation of pointers.
+    if(!in_buf || !out_buf || !out_len) { return -1; }
+
+    // Initialize buffer pointers and lengths.
+    in_buf_ptr = in_buf;
+    in_len_rem = in_len;
+
+    // Set parameters based on whether we're unsquashing or uncrushing.
+    if(squash) { Bits = SQBITS; }
+    else
+    {
+        Bits = CRBITS;
+        if(in_len_rem > 0)
+        {
+            // Crunch format has a header byte indicating max bits.
+            if(*in_buf_ptr != CRBITS) return -1;
+            in_buf_ptr++;
+            in_len_rem--;
+        }
+    }
+
+    if(in_len_rem <= 0)
+    {
+        *out_len = 0;
+        return 0;
+    }
+
+    // Initialize LZW parameters.
+    max_maxcode = 1 << Bits;
+    clear_flg   = 0;
+    n_bits      = INIT_BITS;
+    maxcode     = MAXCODE(n_bits);
+
+    // Allocate memory for LZW tables.
+    prefix = (unsigned short *)malloc(max_maxcode * sizeof(unsigned short));
+    suffix = (unsigned char *)malloc(max_maxcode * sizeof(unsigned char));
+    stack  = (unsigned char *)malloc(max_maxcode * sizeof(unsigned char));
+
+    if(!prefix || !suffix || !stack)
+    {
+        if(prefix) free(prefix);
+        if(suffix) free(suffix);
+        if(stack) free(stack);
+        return -1;
+    }
+
+    // Initialize the first 256 entries of the dictionary.
+    memset(prefix, 0, 256 * sizeof(unsigned short));
+    for(int code = 255; code >= 0; code--) { suffix[code] = (unsigned char)code; }
+
+    free_ent = FIRST;
+    offset   = 0;
+
+    // Main decompression loop.
+    int finchar, oldcode, incode;
+    finchar = oldcode = getcode();
+    if(oldcode == -1)
+    {
+        *out_len = 0;
+        free(prefix);
+        free(suffix);
+        free(stack);
+        return 0;
+    }
+
+    size_t out_pos = 0;
+    if(out_pos < *out_len) { out_buf[out_pos++] = finchar; }
+
+    unsigned char *stackp = stack;
+    int            code;
+    while((code = getcode()) > -1)
+    {
+        if(code == CLEAR)
+        {
+            // Clear the dictionary.
+            memset(prefix, 0, 256 * sizeof(unsigned short));
+            clear_flg = 1;
+            free_ent  = FIRST - 1;
+            if((code = getcode()) == -1) break;
+        }
+        incode = code;
+        // Handle KwKwK case.
+        if(code >= free_ent)
+        {
+            if(code > free_ent)
+            {
+                // Error: invalid code.
+                break;
+            }
+            *stackp++ = finchar;
+            code      = oldcode;
+        }
+        // Decode the string by traversing the dictionary.
+        while(code >= 256)
+        {
+            *stackp++ = suffix[code];
+            code      = prefix[code];
+        }
+        *stackp++ = finchar = suffix[code];
+
+        // Write the decoded string to the output buffer.
+        do {
+            if(out_pos < *out_len) { out_buf[out_pos++] = *--stackp; }
+            else
+            {
+                stackp--;  // Discard if output buffer is full.
+            }
+        } while(stackp > stack);
+
+        // Add the new string to the dictionary.
+        if((code = free_ent) < max_maxcode)
+        {
+            prefix[code] = (unsigned short)oldcode;
+            suffix[code] = finchar;
+            free_ent     = code + 1;
+        }
+        oldcode = incode;
+    }
+
+    // Clean up and return.
+    *out_len = out_pos;
+    free(prefix);
+    free(suffix);
+    free(stack);
+    return 0;
+}
+
+// Decompresses squashed data.
+AARU_EXPORT int AARU_CALL arc_decompress_squash(const unsigned char *in_buf, size_t in_len, unsigned char *out_buf,
+                                                size_t *out_len)
+{
+    return arc_decompress_lzw(in_buf, in_len, out_buf, out_len, 1);
+}
+
+// Decompresses crunched data.
+AARU_EXPORT int AARU_CALL arc_decompress_crunch_dynamic(const unsigned char *in_buf, size_t in_len,
+                                                        unsigned char *out_buf, size_t *out_len)
+{
+    // Allocate a temporary buffer.
+    size_t         temp_len = *out_len * 2;  // Heuristic.
+    unsigned char *temp_buf = malloc(temp_len);
+    if(!temp_buf) return -1;
+
+    // Decompress crunched data.
+    int result = arc_decompress_lzw(in_buf, in_len, temp_buf, &temp_len, 0);
+    if(result == 0)
+    {
+        // Decompress non-repeat packing.
+        result = arc_decompress_pack(temp_buf, temp_len, out_buf, out_len);
+    }
+
+    free(temp_buf);
+    return result;
+}

library.h

@@ -134,4 +134,12 @@ AARU_EXPORT int AARU_CALL arc_decompress_crunch_nrpack(const unsigned char *in_b
 AARU_EXPORT int AARU_CALL arc_decompress_crunch_nrpack_new(const unsigned char *in_buf, size_t in_len,
                                                            unsigned char *out_buf, size_t *out_len);
 
+// Method 8: Dynamic LZW (crunching)
+AARU_EXPORT int AARU_CALL arc_decompress_crunch_dynamic(const unsigned char *in_buf, size_t in_len,
+                                                        unsigned char *out_buf, size_t *out_len);
+
+// Method 9: Dynamic LZW with 13 bits (squashing)
+AARU_EXPORT int AARU_CALL arc_decompress_squash(const unsigned char *in_buf, size_t in_len, unsigned char *out_buf,
+                                                size_t *out_len);
+
 #endif  // AARU_COMPRESSION_NATIVE_LIBRARY_H

tests/CMakeLists.txt

@@ -51,9 +51,18 @@ file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/data/arcpack.bin
 file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/data/arcsqueeze.bin
      DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/data/)
 
+file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/data/arccrunchnr.bin
+     DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/data/)
+
+file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/data/arccrunch_dynamic.bin
+     DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/data/)
+
+file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/data/arcsquash.bin
+     DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/data/)
+
 # 'Google_Tests_run' is the target name
 # 'test1.cpp tests2.cpp' are source files with tests
 add_executable(tests_run apple_rle.cpp crc32.c crc32.h adc.cpp bzip2.cpp lzip.cpp lzfse.cpp zstd.cpp lzma.cpp flac.cpp
-               zoo/lzd.cpp arc/pack.cpp lh5.cpp arc/squeeze.cpp
-               arc/crunch.cpp)
+               zoo/lzd.cpp arc/pack.cpp lh5.cpp arc/squeeze.cpp arc/crunch.cpp
+               arc/squash.cpp)
 target_link_libraries(tests_run gtest gtest_main "Aaru.Compression.Native")

tests/arc/crunch.cpp

@@ -77,5 +77,57 @@ TEST_F(crunchFixture, crunch)
 
     free(outBuf);
 
+    EXPECT_EQ(crc, EXPECTED_CRC32);
+}
+
+class crunchDynamicFixture : public ::testing::Test
+{
+public:
+    crunchDynamicFixture()
+    {
+        // initialization;
+        // can also be done in SetUp()
+    }
+
+protected:
+    void SetUp()
+    {
+        char path[PATH_MAX];
+        char filename[PATH_MAX];
+
+        getcwd(path, PATH_MAX);
+        snprintf(filename, PATH_MAX, "%s/data/arccrunch_dynamic.bin", path);
+
+        FILE *file = fopen(filename, "rb");
+        buffer     = (const uint8_t *)malloc(73189);
+        fread((void *)buffer, 1, 73189, file);
+        fclose(file);
+    }
+
+    void TearDown() { free((void *)buffer); }
+
+    ~crunchDynamicFixture()
+    {
+        // resources cleanup, no exceptions allowed
+    }
+
+    // shared user data
+};
+
+TEST_F(crunchDynamicFixture, crunchDynamic)
+{
+    size_t destLen = 152089;
+    size_t srcLen  = 73189;
+    auto  *outBuf  = (uint8_t *)malloc(152089);
+
+    auto err = arc_decompress_crunch_dynamic(buffer, srcLen, outBuf, &destLen);
+
+    EXPECT_EQ(err, 0);
+    EXPECT_EQ(destLen, 152089);
+
+    auto crc = crc32_data(outBuf, 152089);
+
+    free(outBuf);
+
     EXPECT_EQ(crc, EXPECTED_CRC32);
 }

tests/arc/squash.cpp

@@ -0,0 +1,81 @@
+/*
+ * This file is part of the Aaru Data Preservation Suite.
+ * Copyright (c) 2019-2025 Natalia Portillo.
+ *
+ * This library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of the
+ * License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <climits>
+#include <cstddef>
+#include <cstdint>
+
+#include "../../library.h"
+#include "../crc32.h"
+#include "gtest/gtest.h"
+
+#define EXPECTED_CRC32 0x66007dba
+
+static const uint8_t *buffer;
+
+class squashFixture : public ::testing::Test
+{
+public:
+    squashFixture()
+    {
+        // initialization;
+        // can also be done in SetUp()
+    }
+
+protected:
+    void SetUp()
+    {
+        char path[PATH_MAX];
+        char filename[PATH_MAX];
+
+        getcwd(path, PATH_MAX);
+        snprintf(filename, PATH_MAX, "%s/data/arcsquash.bin", path);
+
+        FILE *file = fopen(filename, "rb");
+        buffer     = (const uint8_t *)malloc(67308);
+        fread((void *)buffer, 1, 67308, file);
+        fclose(file);
+    }
+
+    void TearDown() { free((void *)buffer); }
+
+    ~squashFixture()
+    {
+        // resources cleanup, no exceptions allowed
+    }
+
+    // shared user data
+};
+
+TEST_F(squashFixture, squash)
+{
+    size_t destLen = 152089;
+    size_t srcLen  = 67308;
+    auto  *outBuf  = (uint8_t *)malloc(152089);
+
+    auto err = arc_decompress_squash(buffer, srcLen, outBuf, &destLen);
+
+    EXPECT_EQ(err, 0);
+    EXPECT_EQ(destLen, 152089);
+
+    auto crc = crc32_data(outBuf, 152089);
+
+    free(outBuf);
+
+    EXPECT_EQ(crc, EXPECTED_CRC32);
+}