git subrepo pull (merge) --force deps/libchdr

[pcsx_rearmed.git] / deps / libchdr / deps / zstd-1.5.5 / doc / educational_decoder / harness.c

diff --git a/deps/libchdr/deps/zstd-1.5.5/doc/educational_decoder/harness.c b/deps/libchdr/deps/zstd-1.5.5/doc/educational_decoder/harness.c
new file mode 100644 (file)
index 0000000..12c5a80
--- /dev/null
+++ b/deps/libchdr/deps/zstd-1.5.5/doc/educational_decoder/harness.c
@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "zstd_decompress.h"
+
+typedef unsigned char u8;
+
+// If the data doesn't have decompressed size with it, fallback on assuming the
+// compression ratio is at most 16
+#define MAX_COMPRESSION_RATIO (16)
+
+// Protect against allocating too much memory for output
+#define MAX_OUTPUT_SIZE ((size_t)1024 * 1024 * 1024)
+
+// Error message then exit
+#define ERR_OUT(...) { fprintf(stderr, __VA_ARGS__); exit(1); }
+
+
+typedef struct {
+    u8* address;
+    size_t size;
+} buffer_s;
+
+static void freeBuffer(buffer_s b) { free(b.address); }
+
+static buffer_s read_file(const char *path)
+{
+    FILE* const f = fopen(path, "rb");
+    if (!f) ERR_OUT("failed to open file %s \n", path);
+
+    fseek(f, 0L, SEEK_END);
+    size_t const size = (size_t)ftell(f);
+    rewind(f);
+
+    void* const ptr = malloc(size);
+    if (!ptr) ERR_OUT("failed to allocate memory to hold %s \n", path);
+
+    size_t const read = fread(ptr, 1, size, f);
+    if (read != size) ERR_OUT("error while reading file %s \n", path);
+
+    fclose(f);
+    buffer_s const b = { ptr, size };
+    return b;
+}
+
+static void write_file(const char* path, const u8* ptr, size_t size)
+{
+    FILE* const f = fopen(path, "wb");
+    if (!f) ERR_OUT("failed to open file %s \n", path);
+
+    size_t written = 0;
+    while (written < size) {
+        written += fwrite(ptr+written, 1, size, f);
+        if (ferror(f)) ERR_OUT("error while writing file %s\n", path);
+    }
+
+    fclose(f);
+}
+
+int main(int argc, char **argv)
+{
+    if (argc < 3)
+        ERR_OUT("usage: %s <file.zst> <out_path> [dictionary] \n", argv[0]);
+
+    buffer_s const input = read_file(argv[1]);
+
+    buffer_s dict = { NULL, 0 };
+    if (argc >= 4) {
+        dict = read_file(argv[3]);
+    }
+
+    size_t out_capacity = ZSTD_get_decompressed_size(input.address, input.size);
+    if (out_capacity == (size_t)-1) {
+        out_capacity = MAX_COMPRESSION_RATIO * input.size;
+        fprintf(stderr, "WARNING: Compressed data does not contain "
+                        "decompressed size, going to assume the compression "
+                        "ratio is at most %d (decompressed size of at most "
+                        "%u) \n",
+                MAX_COMPRESSION_RATIO, (unsigned)out_capacity);
+    }
+    if (out_capacity > MAX_OUTPUT_SIZE)
+        ERR_OUT("Required output size too large for this implementation \n");
+
+    u8* const output = malloc(out_capacity);
+    if (!output) ERR_OUT("failed to allocate memory \n");
+
+    dictionary_t* const parsed_dict = create_dictionary();
+    if (dict.size) {
+#if defined (ZDEC_NO_DICTIONARY)
+        printf("dict.size = %zu \n", dict.size);
+        ERR_OUT("no dictionary support \n");
+#else
+        parse_dictionary(parsed_dict, dict.address, dict.size);
+#endif
+    }
+    size_t const decompressed_size =
+        ZSTD_decompress_with_dict(output, out_capacity,
+                                  input.address, input.size,
+                                  parsed_dict);
+
+    free_dictionary(parsed_dict);
+
+    write_file(argv[2], output, decompressed_size);
+
+    freeBuffer(input);
+    freeBuffer(dict);
+    free(output);
+    return 0;
+}