Add ARC non-repeat packing decompression implementation and tests.

CMakeLists.txt

@@ -139,7 +139,8 @@ add_library("Aaru.Compression.Native" SHARED library.c apple_rle.c apple_rle.h a
             zoo/lh5.c
             zoo/lzh.h
             zoo/ar.h
-            zoo/maketbl.c)
+            zoo/maketbl.c
+            arc/pack.c)
 
 include(3rdparty/bzip2.cmake)
 include(3rdparty/flac.cmake)

arc/pack.c

@@ -0,0 +1,78 @@
+/*
+ * 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 <stdint.h>
+#include <string.h>
+#include "../library.h"
+
+#define DLE 0x90  // Data Link Escape character, used as a repeat marker.
+
+// Decompresses data using non-repeat packing.
+// This algorithm encodes runs of identical bytes.
+int arc_decompress_pack(const unsigned char *in_buf, size_t in_len, unsigned char *out_buf, size_t *out_len)
+{
+    // Basic validation of pointers.
+    if(!in_buf || !out_buf || !out_len) { return -1; }
+
+    size_t        in_pos  = 0;
+    size_t        out_pos = 0;
+    unsigned char state   = 0;  // 0 for normal (NOHIST), 1 for in-repeat (INREP).
+    unsigned char lastc   = 0;  // Last character seen.
+
+    // Loop through the input buffer until it's exhausted or the output buffer is full.
+    while(in_pos < in_len && out_pos < *out_len)
+    {
+        if(state == 1)
+        {  // We are in a repeat sequence.
+            if(in_buf[in_pos])
+            {  // The byte after DLE is the repeat count.
+                unsigned char count = in_buf[in_pos];
+                // Write the last character 'count' times.
+                while(--count && out_pos < *out_len) { out_buf[out_pos++] = lastc; }
+            }
+            else
+            {  // A count of 0 means the DLE character itself should be written.
+                if(out_pos < *out_len) { out_buf[out_pos++] = DLE; }
+            }
+            state = 0;  // Return to normal state.
+            in_pos++;
+        }
+        else
+        {  // Normal state.
+            if(in_buf[in_pos] != DLE)
+            {  // Not a repeat sequence.
+                if(out_pos < *out_len)
+                {
+                    // Copy the character and save it as the last character.
+                    out_buf[out_pos++] = lastc = in_buf[in_pos];
+                }
+            }
+            else
+            {               // DLE marks the start of a repeat sequence.
+                state = 1;  // Enter repeat state.
+            }
+            in_pos++;
+        }
+    }
+
+    // Update the output length to the number of bytes written.
+    *out_len = out_pos;
+    // Return success.
+    return 0;
+}

library.h

@@ -118,4 +118,7 @@ AARU_EXPORT int AARU_CALL lh5_decompress(const uint8_t *in_buf, size_t in_len, u
 
 AARU_EXPORT uint64_t AARU_CALL AARU_get_acn_version();
 
+// ARC method 3: Stored with non-repeat packing
+AARU_EXPORT int AARU_CALL arc_decompress_pack(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

@@ -45,9 +45,13 @@ file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/data/alice29.lzd
 file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/data/alice29.lh5
      DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/data/)
 
+file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/data/arcpack.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
+               zoo/lzd.cpp arc/pack.cpp
-               lh5.cpp)
+               lh5.cpp
+               arc/pack.cpp)
 target_link_libraries(tests_run gtest gtest_main "Aaru.Compression.Native")

tests/arc/pack.cpp

@@ -0,0 +1,82 @@
+/*
+ * 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 packFixture : public ::testing::Test
+{
+public:
+    packFixture()
+    {
+        // 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/arcpack.bin", path);
+
+        FILE *file = fopen(filename, "rb");
+        buffer     = (const uint8_t *)malloc(149855);
+        fread((void *)buffer, 1, 149855, file);
+        fclose(file);
+    }
+
+    void TearDown() { free((void *)buffer); }
+
+    ~packFixture()
+    {
+        // resources cleanup, no exceptions allowed
+    }
+
+    // shared user data
+};
+
+TEST_F(packFixture, pack)
+{
+    uint8_t params[] = {0x5D, 0x00, 0x00, 0x00, 0x02};
+    size_t  destLen  = 152089;
+    size_t  srcLen   = 149855;
+    auto   *outBuf   = (uint8_t *)malloc(152089);
+
+    auto err = arc_decompress_pack(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);
+}