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-rw-r--r--chunk-format.h73
1 files changed, 73 insertions, 0 deletions
diff --git a/chunk-format.h b/chunk-format.h
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+#ifndef CHUNK_FORMAT_H
+#define CHUNK_FORMAT_H
+
+#include "hash-ll.h"
+
+struct hashfile;
+struct chunkfile;
+
+#define CHUNK_TOC_ENTRY_SIZE (sizeof(uint32_t) + sizeof(uint64_t))
+
+/*
+ * Initialize a 'struct chunkfile' for writing _or_ reading a file
+ * with the chunk format.
+ *
+ * If writing a file, supply a non-NULL 'struct hashfile *' that will
+ * be used to write.
+ *
+ * If reading a file, use a NULL 'struct hashfile *' and then call
+ * read_table_of_contents(). Supply the memory-mapped data to the
+ * pair_chunk() or read_chunk() methods, as appropriate.
+ *
+ * DO NOT MIX THESE MODES. Use different 'struct chunkfile' instances
+ * for reading and writing.
+ */
+struct chunkfile *init_chunkfile(struct hashfile *f);
+void free_chunkfile(struct chunkfile *cf);
+int get_num_chunks(struct chunkfile *cf);
+typedef int (*chunk_write_fn)(struct hashfile *f, void *data);
+void add_chunk(struct chunkfile *cf,
+ uint32_t id,
+ size_t size,
+ chunk_write_fn fn);
+int write_chunkfile(struct chunkfile *cf, void *data);
+
+int read_table_of_contents(struct chunkfile *cf,
+ const unsigned char *mfile,
+ size_t mfile_size,
+ uint64_t toc_offset,
+ int toc_length,
+ unsigned expected_alignment);
+
+#define CHUNK_NOT_FOUND (-2)
+
+/*
+ * Find 'chunk_id' in the given chunkfile and assign the
+ * given pointer to the position in the mmap'd file where
+ * that chunk begins. Likewise the "size" parameter is filled
+ * with the size of the chunk.
+ *
+ * Returns CHUNK_NOT_FOUND if the chunk does not exist.
+ */
+int pair_chunk(struct chunkfile *cf,
+ uint32_t chunk_id,
+ const unsigned char **p,
+ size_t *size);
+
+typedef int (*chunk_read_fn)(const unsigned char *chunk_start,
+ size_t chunk_size, void *data);
+/*
+ * Find 'chunk_id' in the given chunkfile and call the
+ * given chunk_read_fn method with the information for
+ * that chunk.
+ *
+ * Returns CHUNK_NOT_FOUND if the chunk does not exist.
+ */
+int read_chunk(struct chunkfile *cf,
+ uint32_t chunk_id,
+ chunk_read_fn fn,
+ void *data);
+
+uint8_t oid_version(const struct git_hash_algo *algop);
+
+#endif