Add Apple ADC algorithm.

CMakeLists.txt

@@ -71,6 +71,6 @@ if("${CMAKE_BUILD_TYPE}" MATCHES "Release")
     endif()
 endif()
 
-add_library("Aaru.Compression.Native" SHARED library.c apple_rle.c apple_rle.h)
+add_library("Aaru.Compression.Native" SHARED library.c apple_rle.c apple_rle.h adc.c adc.h)
 
 add_subdirectory(tests)

adc.c

@@ -0,0 +1,125 @@
+//
+// Created by claunia on 17/10/21.
+//
+
+#include <stdint.h>
+#include <string.h>
+
+#include "library.h"
+#include "adc.h"
+
+FORCE_INLINE int GetChunkType(uint8_t byt)
+{
+    if(byt & 0x80) return ADC_PLAIN;
+    if(byt & 0x40) return ADC_THREE_BYTE;
+    return ADC_TWO_BYTE;
+}
+
+FORCE_INLINE int GetChunkSize(uint8_t byt)
+{
+    switch(GetChunkType(byt))
+    {
+        case ADC_PLAIN: return (byt & 0x7F) + 1;
+        case ADC_TWO_BYTE: return ((byt & 0x3F) >> 2) + 3;
+        case ADC_THREE_BYTE: return (byt & 0x3F) + 4;
+        default: return -1;
+    }
+}
+
+FORCE_INLINE int GetOffset(uint8_t chunk[])
+{
+    switch(GetChunkType(chunk[0]))
+    {
+        case ADC_PLAIN: return 0;
+        case ADC_TWO_BYTE: return ((chunk[0] & 0x03) << 8) + chunk[1];
+        case ADC_THREE_BYTE: return (chunk[1] << 8) + chunk[2];
+        default: return -1;
+    }
+}
+
+AARU_EXPORT int32_t AARU_CALL adc_decode_buffer(uint8_t*       dst_buffer,
+                                                int32_t        dst_size,
+                                                const uint8_t* src_buffer,
+                                                int32_t        src_size)
+{
+    int     inputPosition = 0;
+    int     chunkSize;
+    int     offset;
+    int     chunkType;
+    int     outPosition = 0;
+    uint8_t temp[3];
+    uint8_t readByte;
+    uint8_t lastByte;
+    int     i;
+
+    while(inputPosition < src_size)
+    {
+        readByte = src_buffer[inputPosition++];
+
+        chunkType = GetChunkType(readByte);
+
+        switch(chunkType)
+        {
+            case ADC_PLAIN:
+                chunkSize = GetChunkSize(readByte);
+                if(outPosition + chunkSize > dst_size) goto finished;
+                memcpy(dst_buffer + outPosition, src_buffer + inputPosition, chunkSize);
+                outPosition += chunkSize;
+                inputPosition += chunkSize;
+                break;
+            case ADC_TWO_BYTE:
+                chunkSize = GetChunkSize(readByte);
+                temp[0]   = readByte;
+                temp[1]   = src_buffer[inputPosition++];
+                offset    = GetOffset(temp);
+                if(outPosition + chunkSize > dst_size) goto finished;
+                if(offset == 0)
+                {
+                    lastByte = dst_buffer[outPosition - 1];
+                    for(i = 0; i < chunkSize; i++)
+                    {
+                        dst_buffer[outPosition] = lastByte;
+                        outPosition++;
+                    }
+                }
+                else
+                {
+                    for(i = 0; i < chunkSize; i++)
+                    {
+                        dst_buffer[outPosition] = dst_buffer[outPosition - offset - 1];
+                        outPosition++;
+                    }
+                }
+                break;
+            case ADC_THREE_BYTE:
+                chunkSize = GetChunkSize(readByte);
+                temp[0]   = readByte;
+                temp[1]   = src_buffer[inputPosition++];
+                temp[2]   = src_buffer[inputPosition++];
+                offset    = GetOffset(temp);
+
+                if(outPosition + chunkSize > dst_size) goto finished;
+                if(offset == 0)
+                {
+                    lastByte = dst_buffer[outPosition - 1];
+                    for(i = 0; i < chunkSize; i++)
+                    {
+                        dst_buffer[outPosition] = lastByte;
+                        outPosition++;
+                    }
+                }
+                else
+                {
+                    for(i = 0; i < chunkSize; i++)
+                    {
+                        dst_buffer[outPosition] = dst_buffer[outPosition - offset - 1];
+                        outPosition++;
+                    }
+                }
+                break;
+        }
+    }
+
+finished:
+    return outPosition;
+}

adc.h

@@ -0,0 +1,17 @@
+//
+// Created by claunia on 17/10/21.
+//
+
+#ifndef AARU_COMPRESSION_NATIVE__ADC_H_
+#define AARU_COMPRESSION_NATIVE__ADC_H_
+
+#define ADC_PLAIN 1
+#define ADC_TWO_BYTE 2
+#define ADC_THREE_BYTE 3
+
+AARU_EXPORT int32_t AARU_CALL adc_decode_buffer(uint8_t*       dst_buffer,
+                                                int32_t        dst_size,
+                                                const uint8_t* src_buffer,
+                                                int32_t        src_size);
+
+#endif // AARU_COMPRESSION_NATIVE__ADC_H_

tests/CMakeLists.txt

@@ -12,7 +12,10 @@ include_directories(${gtest_SOURCE_DIR}/include ${gtest_SOURCE_DIR})
 file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/data/apple_rle.bin
      DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/data/)
 
+file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/data/adc.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)
+add_executable(tests_run apple_rle.cpp crc32.c crc32.h adc.cpp)
 target_link_libraries(tests_run gtest gtest_main "Aaru.Compression.Native")

tests/adc.cpp

@@ -0,0 +1,79 @@
+/*
+ * This file is part of the Aaru Data Preservation Suite.
+ * Copyright (c) 2019-2021 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 <cstdint>
+#include <cstring>
+
+#include "../library.h"
+#include "../adc.h"
+#include "crc32.h"
+#include "gtest/gtest.h"
+
+#define EXPECTED_CRC32 0x5a5a7388
+
+static const uint8_t* buffer;
+
+class adcFixture : public ::testing::Test
+{
+  public:
+    adcFixture()
+    {
+        // 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/adc.bin", path);
+
+        FILE* file = fopen(filename, "rb");
+        buffer     = (const uint8_t*)malloc(34367);
+        fread((void*)buffer, 1, 34367, file);
+        fclose(file);
+    }
+
+    void TearDown() { free((void*)buffer); }
+
+    ~adcFixture()
+    {
+        // resources cleanup, no exceptions allowed
+    }
+
+    // shared user data
+};
+
+TEST_F(adcFixture, adc)
+{
+    auto* outBuf = (uint8_t*)malloc(327680);
+
+    auto decoded = adc_decode_buffer(outBuf, 327680, buffer, 34367);
+
+    EXPECT_EQ(decoded, 262144);
+
+    auto crc = crc32_data(outBuf, 262144);
+
+    free(outBuf);
+
+    EXPECT_EQ(crc, EXPECTED_CRC32);
+}