Merge pull request #6192 from libgit2/ethomson/sha256_preparation

SHA256: early preparation

examples/index-pack.c

@@ -17,7 +17,6 @@ int lg2_index_pack(git_repository *repo, int argc, char **argv)
 	git_indexer *idx;
 	git_indexer_progress stats = {0, 0};
 	int error;
-	char hash[GIT_OID_HEXSZ + 1] = {0};
 	int fd;
 	ssize_t read_bytes;
 	char buf[512];
@@ -61,8 +60,7 @@ int lg2_index_pack(git_repository *repo, int argc, char **argv)
 
 	printf("\rIndexing %u of %u\n", stats.indexed_objects, stats.total_objects);
 
-	git_oid_fmt(hash, git_indexer_hash(idx));
-	puts(hash);
+	puts(git_indexer_name(idx));
 
  cleanup:
 	close(fd);

fuzzers/packfile_fuzzer.c

@@ -101,13 +101,13 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
 	if (git_indexer_commit(indexer, &stats) < 0)
 		goto cleanup;
 
-	if (git_str_printf(&path, "pack-%s.idx", git_oid_tostr_s(git_indexer_hash(indexer))) < 0)
+	if (git_str_printf(&path, "pack-%s.idx", git_indexer_name(indexer)) < 0)
 		goto cleanup;
 	p_unlink(git_str_cstr(&path));
 
 	git_str_clear(&path);
 
-	if (git_str_printf(&path, "pack-%s.pack", git_oid_tostr_s(git_indexer_hash(indexer))) < 0)
+	if (git_str_printf(&path, "pack-%s.pack", git_indexer_name(indexer)) < 0)
 		goto cleanup;
 	p_unlink(git_str_cstr(&path));
 

include/git2/index.h

@@ -296,6 +296,7 @@ GIT_EXTERN(int) git_index_write(git_index *index);
  */
 GIT_EXTERN(const char *) git_index_path(const git_index *index);
 
+#ifndef GIT_DEPRECATE_HARD
 /**
  * Get the checksum of the index
  *
@@ -303,10 +304,12 @@ GIT_EXTERN(const char *) git_index_path(const git_index *index);
  * last 20 bytes which are the checksum itself). In cases where the
  * index does not exist on-disk, it will be zeroed out.
  *
+ * @deprecated this function is deprecated with no replacement
  * @param index an existing index object
  * @return a pointer to the checksum of the index
  */
 GIT_EXTERN(const git_oid *) git_index_checksum(git_index *index);
+#endif
 
 /**
  * Read a tree into the index file with stats

include/git2/indexer.h

@@ -129,16 +129,30 @@ GIT_EXTERN(int) git_indexer_append(git_indexer *idx, const void *data, size_t si
  */
 GIT_EXTERN(int) git_indexer_commit(git_indexer *idx, git_indexer_progress *stats);
 
+#ifndef GIT_DEPRECATE_HARD
 /**
  * Get the packfile's hash
  *
  * A packfile's name is derived from the sorted hashing of all object
  * names. This is only correct after the index has been finalized.
  *
+ * @deprecated use git_indexer_name
  * @param idx the indexer instance
  * @return the packfile's hash
  */
 GIT_EXTERN(const git_oid *) git_indexer_hash(const git_indexer *idx);
+#endif
+
+/**
+ * Get the unique name for the resulting packfile.
+ *
+ * The packfile's name is derived from the packfile's content.
+ * This is only correct after the index has been finalized.
+ *
+ * @param idx the indexer instance
+ * @return a NUL terminated string for the packfile name
+ */
+GIT_EXTERN(const char *) git_indexer_name(const git_indexer *idx);
 
 /**
  * Free the indexer and its resources

include/git2/pack.h

@@ -170,16 +170,30 @@ GIT_EXTERN(int) git_packbuilder_write(
 	git_indexer_progress_cb progress_cb,
 	void *progress_cb_payload);
 
+#ifndef GIT_DEPRECATE_HARD
 /**
-* Get the packfile's hash
-*
-* A packfile's name is derived from the sorted hashing of all object
-* names. This is only correct after the packfile has been written.
-*
-* @param pb The packbuilder object
+ * Get the packfile's hash
+ *
+ * A packfile's name is derived from the sorted hashing of all object
+ * names. This is only correct after the packfile has been written.
+ *
+ * @deprecated use git_packbuilder_name
+ * @param pb The packbuilder object
  * @return 0 or an error code
-*/
+ */
 GIT_EXTERN(const git_oid *) git_packbuilder_hash(git_packbuilder *pb);
+#endif
+
+/**
+ * Get the unique name for the resulting packfile.
+ *
+ * The packfile's name is derived from the packfile's content.
+ * This is only correct after the packfile has been written.
+ *
+ * @param pb the packbuilder instance
+ * @return a NUL terminated string for the packfile name
+ */
+GIT_EXTERN(const char *) git_packbuilder_name(git_packbuilder *pb);
 
 /**
  * Callback used to iterate over packed objects

src/branch.c

@@ -123,7 +123,10 @@ int git_branch_create(
 	const git_commit *commit,
 	int force)
 {
-	return create_branch(ref_out, repository, branch_name, commit, git_oid_tostr_s(git_commit_id(commit)), force);
+	char commit_id[GIT_OID_HEXSZ + 1];
+
+	git_oid_tostr(commit_id, GIT_OID_HEXSZ + 1, git_commit_id(commit));
+	return create_branch(ref_out, repository, branch_name, commit, commit_id, force);
 }
 
 int git_branch_create_from_annotated(

src/commit_graph.c

@@ -201,7 +201,8 @@ int git_commit_graph_file_parse(
 	struct git_commit_graph_chunk *last_chunk;
 	uint32_t i;
 	off64_t last_chunk_offset, chunk_offset, trailer_offset;
-	git_oid cgraph_checksum = {{0}};
+	unsigned char checksum[GIT_HASH_SHA1_SIZE];
+	size_t checksum_size;
 	int error;
 	struct git_commit_graph_chunk chunk_oid_fanout = {0}, chunk_oid_lookup = {0},
 				      chunk_commit_data = {0}, chunk_extra_edge_list = {0},
@@ -227,13 +228,15 @@ int git_commit_graph_file_parse(
 	 */
 	last_chunk_offset = sizeof(struct git_commit_graph_header) + (1 + hdr->chunks) * 12;
 	trailer_offset = size - GIT_OID_RAWSZ;
+	checksum_size = GIT_HASH_SHA1_SIZE;
+
 	if (trailer_offset < last_chunk_offset)
 		return commit_graph_error("wrong commit-graph size");
-	git_oid_cpy(&file->checksum, (git_oid *)(data + trailer_offset));
+	memcpy(file->checksum, (data + trailer_offset), checksum_size);
 
-	if (git_hash_buf(cgraph_checksum.id, data, (size_t)trailer_offset, GIT_HASH_ALGORITHM_SHA1) < 0)
+	if (git_hash_buf(checksum, data, (size_t)trailer_offset, GIT_HASH_ALGORITHM_SHA1) < 0)
 		return commit_graph_error("could not calculate signature");
-	if (!git_oid_equal(&cgraph_checksum, &file->checksum))
+	if (memcmp(checksum, file->checksum, checksum_size) != 0)
 		return commit_graph_error("index signature mismatch");
 
 	chunk_hdr = data + sizeof(struct git_commit_graph_header);
@@ -476,7 +479,8 @@ bool git_commit_graph_file_needs_refresh(const git_commit_graph_file *file, cons
 	git_file fd = -1;
 	struct stat st;
 	ssize_t bytes_read;
-	git_oid cgraph_checksum = {{0}};
+	unsigned char checksum[GIT_HASH_SHA1_SIZE];
+	size_t checksum_size = GIT_HASH_SHA1_SIZE;
 
 	/* TODO: properly open the file without access time using O_NOATIME */
 	fd = git_futils_open_ro(path);
@@ -494,12 +498,12 @@ bool git_commit_graph_file_needs_refresh(const git_commit_graph_file *file, cons
 		return true;
 	}
 
-	bytes_read = p_pread(fd, cgraph_checksum.id, GIT_OID_RAWSZ, st.st_size - GIT_OID_RAWSZ);
+	bytes_read = p_pread(fd, checksum, checksum_size, st.st_size - checksum_size);
 	p_close(fd);
-	if (bytes_read != GIT_OID_RAWSZ)
+	if (bytes_read != (ssize_t)checksum_size)
 		return true;
 
-	return !git_oid_equal(&cgraph_checksum, &file->checksum);
+	return (memcmp(checksum, file->checksum, checksum_size) != 0);
 }
 
 int git_commit_graph_entry_find(
@@ -974,7 +978,8 @@ static int commit_graph_write(
 	off64_t offset;
 	git_str oid_lookup = GIT_STR_INIT, commit_data = GIT_STR_INIT,
 		extra_edge_list = GIT_STR_INIT;
-	git_oid cgraph_checksum = {{0}};
+	unsigned char checksum[GIT_HASH_SHA1_SIZE];
+	size_t checksum_size;
 	git_hash_ctx ctx;
 	struct commit_graph_write_hash_context hash_cb_data = {0};
 
@@ -987,6 +992,7 @@ static int commit_graph_write(
 	hash_cb_data.cb_data = cb_data;
 	hash_cb_data.ctx = &ctx;
 
+	checksum_size = GIT_HASH_SHA1_SIZE;
 	error = git_hash_ctx_init(&ctx, GIT_HASH_ALGORITHM_SHA1);
 	if (error < 0)
 		return error;
@@ -1133,10 +1139,10 @@ static int commit_graph_write(
 		goto cleanup;
 
 	/* Finalize the checksum and write the trailer. */
-	error = git_hash_final(cgraph_checksum.id, &ctx);
+	error = git_hash_final(checksum, &ctx);
 	if (error < 0)
 		goto cleanup;
-	error = write_cb((const char *)&cgraph_checksum, sizeof(cgraph_checksum), cb_data);
+	error = write_cb((char *)checksum, checksum_size, cb_data);
 	if (error < 0)
 		goto cleanup;
 

src/commit_graph.h

@@ -15,6 +15,8 @@
 
 #include "map.h"
 #include "vector.h"
+#include "oid.h"
+#include "hash.h"
 
 /**
  * A commit-graph file.
@@ -55,7 +57,7 @@ typedef struct git_commit_graph_file {
 	size_t num_extra_edge_list;
 
 	/* The trailer of the file. Contains the SHA1-checksum of the whole file. */
-	git_oid checksum;
+	unsigned char checksum[GIT_HASH_SHA1_SIZE];
 } git_commit_graph_file;
 
 /**

src/config_file.c

@@ -19,13 +19,14 @@
 #include "regexp.h"
 #include "sysdir.h"
 #include "wildmatch.h"
+#include "hash.h"
 
 /* Max depth for [include] directives */
 #define MAX_INCLUDE_DEPTH 10
 
 typedef struct config_file {
 	git_futils_filestamp stamp;
-	git_oid checksum;
+	unsigned char checksum[GIT_HASH_SHA1_SIZE];
 	char *path;
 	git_array_t(struct config_file) includes;
 } config_file;
@@ -132,7 +133,7 @@ static int config_file_is_modified(int *modified, config_file *file)
 {
 	config_file *include;
 	git_str buf = GIT_STR_INIT;
-	git_oid hash;
+	unsigned char checksum[GIT_HASH_SHA1_SIZE];
 	uint32_t i;
 	int error = 0;
 
@@ -144,10 +145,10 @@ static int config_file_is_modified(int *modified, config_file *file)
 	if ((error = git_futils_readbuffer(&buf, file->path)) < 0)
 		goto out;
 
-	if ((error = git_hash_buf(hash.id, buf.ptr, buf.size, GIT_HASH_ALGORITHM_SHA1)) < 0)
+	if ((error = git_hash_buf(checksum, buf.ptr, buf.size, GIT_HASH_ALGORITHM_SHA1)) < 0)
 		goto out;
 
-	if (!git_oid_equal(&hash, &file->checksum)) {
+	if (memcmp(checksum, file->checksum, GIT_HASH_SHA1_SIZE) != 0) {
 		*modified = 1;
 		goto out;
 	}
@@ -880,7 +881,7 @@ static int config_file_read(
 		goto out;
 
 	git_futils_filestamp_set_from_stat(&file->stamp, &st);
-	if ((error = git_hash_buf(file->checksum.id, contents.ptr, contents.size, GIT_HASH_ALGORITHM_SHA1)) < 0)
+	if ((error = git_hash_buf(file->checksum, contents.ptr, contents.size, GIT_HASH_ALGORITHM_SHA1)) < 0)
 		goto out;
 
 	if ((error = config_file_read_buffer(entries, repo, file, level, depth,

src/hash.c

@@ -124,3 +124,19 @@ done:
 
 	return error;
 }
+
+int git_hash_fmt(char *out, unsigned char *hash, size_t hash_len)
+{
+	static char hex[] = "0123456789abcdef";
+	char *str = out;
+	size_t i;
+
+	for (i = 0; i < hash_len; i++) {
+		*str++ = hex[hash[i] >> 4];
+		*str++ = hex[hash[i] & 0x0f];
+	}
+
+	*str++ = '\0';
+
+	return 0;
+}

src/hash.h

@@ -41,4 +41,6 @@ int git_hash_final(unsigned char *out, git_hash_ctx *c);
 int git_hash_buf(unsigned char *out, const void *data, size_t len, git_hash_algorithm_t algorithm);
 int git_hash_vec(unsigned char *out, git_str_vec *vec, size_t n, git_hash_algorithm_t algorithm);
 
+int git_hash_fmt(char *out, unsigned char *hash, size_t hash_len);
+
 #endif

src/index.c

@@ -34,7 +34,6 @@ static int index_apply_to_wd_diff(git_index *index, int action, const git_strarr
 
 #define minimal_entry_size (offsetof(struct entry_short, path))
 
-static const size_t INDEX_FOOTER_SIZE = GIT_OID_RAWSZ;
 static const size_t INDEX_HEADER_SIZE = 12;
 
 static const unsigned int INDEX_VERSION_NUMBER_DEFAULT = 2;
@@ -121,7 +120,7 @@ static int read_header(struct index_header *dest, const void *buffer);
 
 static int parse_index(git_index *index, const char *buffer, size_t buffer_size);
 static bool is_index_extended(git_index *index);
-static int write_index(git_oid *checksum, git_index *index, git_filebuf *file);
+static int write_index(unsigned char checksum[GIT_HASH_SHA1_SIZE], size_t *checksum_size, git_index *index, git_filebuf *file);
 
 static void index_entry_free(git_index_entry *entry);
 static void index_entry_reuc_free(git_index_reuc_entry *reuc);
@@ -607,10 +606,12 @@ int git_index_caps(const git_index *index)
 			(index->no_symlinks ? GIT_INDEX_CAPABILITY_NO_SYMLINKS : 0));
 }
 
+#ifndef GIT_DEPRECATE_HARD
 const git_oid *git_index_checksum(git_index *index)
 {
-	return &index->checksum;
+	return (git_oid *)index->checksum;
 }
+#endif
 
 /**
  * Returns 1 for changed, 0 for not changed and <0 for errors
@@ -619,24 +620,25 @@ static int compare_checksum(git_index *index)
 {
 	int fd;
 	ssize_t bytes_read;
-	git_oid checksum = {{ 0 }};
+	unsigned char checksum[GIT_HASH_SHA1_SIZE];
+	size_t checksum_size = GIT_HASH_SHA1_SIZE;
 
 	if ((fd = p_open(index->index_file_path, O_RDONLY)) < 0)
 		return fd;
 
-	if (p_lseek(fd, -20, SEEK_END) < 0) {
+	if (p_lseek(fd, (0 - (ssize_t)checksum_size), SEEK_END) < 0) {
 		p_close(fd);
 		git_error_set(GIT_ERROR_OS, "failed to seek to end of file");
 		return -1;
 	}
 
-	bytes_read = p_read(fd, &checksum, GIT_OID_RAWSZ);
+	bytes_read = p_read(fd, checksum, checksum_size);
 	p_close(fd);
 
-	if (bytes_read < 0)
+	if (bytes_read < (ssize_t)checksum_size)
 		return -1;
 
-	return !!git_oid_cmp(&checksum, &index->checksum);
+	return !!memcmp(checksum, index->checksum, checksum_size);
 }
 
 int git_index_read(git_index *index, int force)
@@ -703,16 +705,6 @@ int git_index_read_safely(git_index *index)
 	return git_index_read(index, false);
 }
 
-int git_index__changed_relative_to(
-	git_index *index, const git_oid *checksum)
-{
-	/* attempt to update index (ignoring errors) */
-	if (git_index_read(index, false) < 0)
-		git_error_clear();
-
-	return !!git_oid_cmp(&index->checksum, checksum);
-}
-
 static bool is_racy_entry(git_index *index, const git_index_entry *entry)
 {
 	/* Git special-cases submodules in the check */
@@ -2470,8 +2462,9 @@ static int read_entry(
 	git_index_entry entry = {{0}};
 	bool compressed = index->version >= INDEX_VERSION_NUMBER_COMP;
 	char *tmp_path = NULL;
+	size_t checksum_size = GIT_HASH_SHA1_SIZE;
 
-	if (INDEX_FOOTER_SIZE + minimal_entry_size > buffer_size)
+	if (checksum_size + minimal_entry_size > buffer_size)
 		return -1;
 
 	/* buffer is not guaranteed to be aligned */
@@ -2552,7 +2545,7 @@ static int read_entry(
 	if (entry_size == 0)
 		return -1;
 
-	if (INDEX_FOOTER_SIZE + entry_size > buffer_size)
+	if (checksum_size + entry_size > buffer_size)
 		return -1;
 
 	if (index_entry_dup(out, index, &entry) < 0) {
@@ -2586,6 +2579,7 @@ static int read_extension(size_t *read_len, git_index *index, const char *buffer
 {
 	struct index_extension dest;
 	size_t total_size;
+	size_t checksum_size = GIT_HASH_SHA1_SIZE;
 
 	/* buffer is not guaranteed to be aligned */
 	memcpy(&dest, buffer, sizeof(struct index_extension));
@@ -2595,7 +2589,7 @@ static int read_extension(size_t *read_len, git_index *index, const char *buffer
 
 	if (dest.extension_size > total_size ||
 		buffer_size < total_size ||
-		buffer_size - total_size < INDEX_FOOTER_SIZE) {
+		buffer_size - total_size < checksum_size) {
 		index_error_invalid("extension is truncated");
 		return -1;
 	}
@@ -2632,7 +2626,8 @@ static int parse_index(git_index *index, const char *buffer, size_t buffer_size)
 	int error = 0;
 	unsigned int i;
 	struct index_header header = { 0 };
-	git_oid checksum_calculated, checksum_expected;
+	unsigned char checksum[GIT_HASH_SHA1_SIZE];
+	size_t checksum_size = GIT_HASH_SHA1_SIZE;
 	const char *last = NULL;
 	const char *empty = "";
 
@@ -2644,12 +2639,12 @@ static int parse_index(git_index *index, const char *buffer, size_t buffer_size)
 	buffer_size -= _increase;\
 }
 
-	if (buffer_size < INDEX_HEADER_SIZE + INDEX_FOOTER_SIZE)
+	if (buffer_size < INDEX_HEADER_SIZE + checksum_size)
 		return index_error_invalid("insufficient buffer space");
 
 	/* Precalculate the SHA1 of the files's contents -- we'll match it to
 	 * the provided SHA1 in the footer */
-	git_hash_buf(checksum_calculated.id, buffer, buffer_size - INDEX_FOOTER_SIZE, GIT_HASH_ALGORITHM_SHA1);
+	git_hash_buf(checksum, buffer, buffer_size - checksum_size, GIT_HASH_ALGORITHM_SHA1);
 
 	/* Parse header */
 	if ((error = read_header(&header, buffer)) < 0)
@@ -2667,7 +2662,7 @@ static int parse_index(git_index *index, const char *buffer, size_t buffer_size)
 		return error;
 
 	/* Parse all the entries */
-	for (i = 0; i < header.entry_count && buffer_size > INDEX_FOOTER_SIZE; ++i) {
+	for (i = 0; i < header.entry_count && buffer_size > checksum_size; ++i) {
 		git_index_entry *entry = NULL;
 		size_t entry_size;
 
@@ -2699,7 +2694,7 @@ static int parse_index(git_index *index, const char *buffer, size_t buffer_size)
 	}
 
 	/* There's still space for some extensions! */
-	while (buffer_size > INDEX_FOOTER_SIZE) {
+	while (buffer_size > checksum_size) {
 		size_t extension_size;
 
 		if ((error = read_extension(&extension_size, index, buffer, buffer_size)) < 0) {
@@ -2709,22 +2704,20 @@ static int parse_index(git_index *index, const char *buffer, size_t buffer_size)
 		seek_forward(extension_size);
 	}
 
-	if (buffer_size != INDEX_FOOTER_SIZE) {
+	if (buffer_size != checksum_size) {
 		error = index_error_invalid(
 			"buffer size does not match index footer size");
 		goto done;
 	}
 
 	/* 160-bit SHA-1 over the content of the index file before this checksum. */
-	git_oid_fromraw(&checksum_expected, (const unsigned char *)buffer);
-
-	if (git_oid__cmp(&checksum_calculated, &checksum_expected) != 0) {
+	if (memcmp(checksum, buffer, checksum_size) != 0) {
 		error = index_error_invalid(
 			"calculated checksum does not match expected");
 		goto done;
 	}
 
-	git_oid_cpy(&index->checksum, &checksum_calculated);
+	memcpy(index->checksum, checksum, checksum_size);
 
 #undef seek_forward
 
@@ -3040,9 +3033,12 @@ static void clear_uptodate(git_index *index)
 		entry->flags_extended &= ~GIT_INDEX_ENTRY_UPTODATE;
 }
 
-static int write_index(git_oid *checksum, git_index *index, git_filebuf *file)
+static int write_index(
+	unsigned char checksum[GIT_HASH_SHA1_SIZE],
+	size_t *checksum_size,
+	git_index *index,
+	git_filebuf *file)
 {
-	git_oid hash_final;
 	struct index_header header;
 	bool is_extended;
 	uint32_t index_version_number;
@@ -3050,6 +3046,8 @@ static int write_index(git_oid *checksum, git_index *index, git_filebuf *file)
 	GIT_ASSERT_ARG(index);
 	GIT_ASSERT_ARG(file);
 
+	*checksum_size = GIT_HASH_SHA1_SIZE;
+
 	if (index->version <= INDEX_VERSION_NUMBER_EXT)  {
 		is_extended = is_index_extended(index);
 		index_version_number = is_extended ? INDEX_VERSION_NUMBER_EXT : INDEX_VERSION_NUMBER_LB;
@@ -3080,11 +3078,10 @@ static int write_index(git_oid *checksum, git_index *index, git_filebuf *file)
 		return -1;
 
 	/* get out the hash for all the contents we've appended to the file */
-	git_filebuf_hash(hash_final.id, file);
-	git_oid_cpy(checksum, &hash_final);
+	git_filebuf_hash(checksum, file);
 
 	/* write it at the end of the file */
-	if (git_filebuf_write(file, hash_final.id, GIT_OID_RAWSZ) < 0)
+	if (git_filebuf_write(file, checksum, *checksum_size) < 0)
 		return -1;
 
 	/* file entries are no longer up to date */
@@ -3714,8 +3711,9 @@ int git_indexwriter_init_for_operation(
 
 int git_indexwriter_commit(git_indexwriter *writer)
 {
+	unsigned char checksum[GIT_HASH_SHA1_SIZE];
+	size_t checksum_size;
 	int error;
-	git_oid checksum = {{ 0 }};
 
 	if (!writer->should_write)
 		return 0;
@@ -3723,7 +3721,7 @@ int git_indexwriter_commit(git_indexwriter *writer)
 	git_vector_sort(&writer->index->entries);
 	git_vector_sort(&writer->index->reuc);
 
-	if ((error = write_index(&checksum, writer->index, &writer->file)) < 0) {
+	if ((error = write_index(checksum, &checksum_size, writer->index, &writer->file)) < 0) {
 		git_indexwriter_cleanup(writer);
 		return error;
 	}
@@ -3739,7 +3737,7 @@ int git_indexwriter_commit(git_indexwriter *writer)
 
 	writer->index->dirty = 0;
 	writer->index->on_disk = 1;
-	git_oid_cpy(&writer->index->checksum, &checksum);
+	memcpy(writer->index->checksum, checksum, checksum_size);
 
 	git_index_free(writer->index);
 	writer->index = NULL;

src/index.h

@@ -27,7 +27,7 @@ struct git_index {
 
 	char *index_file_path;
 	git_futils_filestamp stamp;
-	git_oid checksum;   /* checksum at the end of the file */
+	unsigned char checksum[GIT_HASH_SHA1_SIZE];
 
 	git_vector entries;
 	git_idxmap *entries_map;
@@ -133,10 +133,13 @@ extern unsigned int git_index__create_mode(unsigned int mode);
 
 GIT_INLINE(const git_futils_filestamp *) git_index__filestamp(git_index *index)
 {
-   return &index->stamp;
+	return &index->stamp;
 }
 
-extern int git_index__changed_relative_to(git_index *index, const git_oid *checksum);
+GIT_INLINE(unsigned char *) git_index__checksum(git_index *index)
+{
+	return index->checksum;
+}
 
 /* Copy the current entries vector *and* increment the index refcount.
  * Call `git_index__release_snapshot` when done.

src/indexer.c

@@ -55,7 +55,8 @@ struct git_indexer {
 	git_vector deltas;
 	unsigned int fanout[256];
 	git_hash_ctx hash_ctx;
-	git_oid hash;
+	unsigned char checksum[GIT_HASH_SHA1_SIZE];
+	char name[(GIT_HASH_SHA1_SIZE * 2) + 1];
 	git_indexer_progress_cb progress_cb;
 	void *progress_payload;
 	char objbuf[8*1024];
@@ -76,9 +77,16 @@ struct delta_info {
 	off64_t delta_off;
 };
 
+#ifndef GIT_DEPRECATE_HARD
 const git_oid *git_indexer_hash(const git_indexer *idx)
 {
-	return &idx->hash;
+	return (git_oid *)idx->checksum;
+}
+#endif
+
+const char *git_indexer_name(const git_indexer *idx)
+{
+	return idx->name;
 }
 
 static int parse_header(struct git_pack_header *hdr, struct git_pack_file *pack)
@@ -897,8 +905,7 @@ static int index_path(git_str *path, git_indexer *idx, const char *suffix)
 
 	git_str_truncate(path, slash);
 	git_str_puts(path, prefix);
-	git_oid_fmt(path->ptr + git_str_len(path), &idx->hash);
-	path->size += GIT_OID_HEXSZ;
+	git_str_puts(path, idx->name);
 	git_str_puts(path, suffix);
 
 	return git_str_oom(path) ? -1 : 0;
@@ -919,12 +926,13 @@ static int inject_object(git_indexer *idx, git_oid *id)
 	git_odb_object *obj = NULL;
 	struct entry *entry = NULL;
 	struct git_pack_entry *pentry = NULL;
-	git_oid foo = {{0}};
+	unsigned char empty_checksum[GIT_HASH_SHA1_SIZE] = {0};
 	unsigned char hdr[64];
 	git_str buf = GIT_STR_INIT;
 	off64_t entry_start;
 	const void *data;
 	size_t len, hdr_len;
+	size_t checksum_size = GIT_HASH_SHA1_SIZE;
 	int error;
 
 	if ((error = seek_back_trailer(idx)) < 0)
@@ -966,7 +974,7 @@ static int inject_object(git_indexer *idx, git_oid *id)
 
 	/* Write a fake trailer so the pack functions play ball */
 
-	if ((error = append_to_pack(idx, &foo, GIT_OID_RAWSZ)) < 0)
+	if ((error = append_to_pack(idx, empty_checksum, checksum_size)) < 0)
 		goto cleanup;
 
 	idx->pack->mwf.size += GIT_OID_RAWSZ;
@@ -1160,9 +1168,11 @@ int git_indexer_commit(git_indexer *idx, git_indexer_progress *stats)
 	struct git_pack_idx_header hdr;
 	git_str filename = GIT_STR_INIT;
 	struct entry *entry;
-	git_oid trailer_hash, file_hash;
+	unsigned char checksum[GIT_HASH_SHA1_SIZE];
 	git_filebuf index_file = {0};
 	void *packfile_trailer;
+	size_t checksum_size = GIT_HASH_SHA1_SIZE;
+	bool mismatch;
 
 	if (!idx->parsed_header) {
 		git_error_set(GIT_ERROR_INDEXER, "incomplete pack header");
@@ -1170,27 +1180,27 @@ int git_indexer_commit(git_indexer *idx, git_indexer_progress *stats)
 	}
 
 	/* Test for this before resolve_deltas(), as it plays with idx->off */
-	if (idx->off + 20 < idx->pack->mwf.size) {
+	if (idx->off + (ssize_t)checksum_size < idx->pack->mwf.size) {
 		git_error_set(GIT_ERROR_INDEXER, "unexpected data at the end of the pack");
 		return -1;
 	}
-	if (idx->off + 20 > idx->pack->mwf.size) {
+	if (idx->off + (ssize_t)checksum_size > idx->pack->mwf.size) {
 		git_error_set(GIT_ERROR_INDEXER, "missing trailer at the end of the pack");
 		return -1;
 	}
 
-	packfile_trailer = git_mwindow_open(&idx->pack->mwf, &w, idx->pack->mwf.size - GIT_OID_RAWSZ, GIT_OID_RAWSZ, &left);
+	packfile_trailer = git_mwindow_open(&idx->pack->mwf, &w, idx->pack->mwf.size - checksum_size, checksum_size, &left);
 	if (packfile_trailer == NULL) {
 		git_mwindow_close(&w);
 		goto on_error;
 	}
 
 	/* Compare the packfile trailer as it was sent to us and what we calculated */
-	git_oid_fromraw(&file_hash, packfile_trailer);
+	git_hash_final(checksum, &idx->trailer);
+	mismatch = !!memcmp(checksum, packfile_trailer, checksum_size);
 	git_mwindow_close(&w);
 
-	git_hash_final(trailer_hash.id, &idx->trailer);
-	if (git_oid_cmp(&file_hash, &trailer_hash)) {
+	if (mismatch) {
 		git_error_set(GIT_ERROR_INDEXER, "packfile trailer mismatch");
 		return -1;
 	}
@@ -1210,8 +1220,8 @@ int git_indexer_commit(git_indexer *idx, git_indexer_progress *stats)
 		if (update_header_and_rehash(idx, stats) < 0)
 			return -1;
 
-		git_hash_final(trailer_hash.id, &idx->trailer);
-		write_at(idx, &trailer_hash, idx->pack->mwf.size - GIT_OID_RAWSZ, GIT_OID_RAWSZ);
+		git_hash_final(checksum, &idx->trailer);
+		write_at(idx, checksum, idx->pack->mwf.size - checksum_size, checksum_size);
 	}
 
 	/*
@@ -1230,7 +1240,9 @@ int git_indexer_commit(git_indexer *idx, git_indexer_progress *stats)
 
 	/* Use the trailer hash as the pack file name to ensure
 	 * files with different contents have different names */
-	git_oid_cpy(&idx->hash, &trailer_hash);
+	memcpy(idx->checksum, checksum, checksum_size);
+	if (git_hash_fmt(idx->name, checksum, checksum_size) < 0)
+		return -1;
 
 	git_str_sets(&filename, idx->pack->pack_name);
 	git_str_shorten(&filename, strlen("pack"));
@@ -1291,14 +1303,14 @@ int git_indexer_commit(git_indexer *idx, git_indexer_progress *stats)
 	}
 
 	/* Write out the packfile trailer to the index */
-	if (git_filebuf_write(&index_file, &trailer_hash, GIT_OID_RAWSZ) < 0)
+	if (git_filebuf_write(&index_file, checksum, checksum_size) < 0)
 		goto on_error;
 
 	/* Write out the hash of the idx */
-	if (git_filebuf_hash(trailer_hash.id, &index_file) < 0)
+	if (git_filebuf_hash(checksum, &index_file) < 0)
 		goto on_error;
 
-	git_filebuf_write(&index_file, &trailer_hash, sizeof(git_oid));
+	git_filebuf_write(&index_file, checksum, checksum_size);
 
 	/* Figure out what the final name should be */
 	if (index_path(&filename, idx, ".idx") < 0)

src/midx.c

@@ -178,7 +178,8 @@ int git_midx_parse(
 	struct git_midx_chunk *last_chunk;
 	uint32_t i;
 	off64_t last_chunk_offset, chunk_offset, trailer_offset;
-	git_oid idx_checksum = {{0}};
+	size_t checksum_size;
+	unsigned char checksum[GIT_HASH_SHA1_SIZE];
 	int error;
 	struct git_midx_chunk chunk_packfile_names = {0},
 					 chunk_oid_fanout = {0},
@@ -208,14 +209,17 @@ int git_midx_parse(
 	last_chunk_offset =
 			sizeof(struct git_midx_header) +
 			(1 + hdr->chunks) * 12;
-	trailer_offset = size - GIT_OID_RAWSZ;
+
+	checksum_size = GIT_HASH_SHA1_SIZE;
+	trailer_offset = size - checksum_size;
+
 	if (trailer_offset < last_chunk_offset)
 		return midx_error("wrong index size");
-	git_oid_cpy(&idx->checksum, (git_oid *)(data + trailer_offset));
+	memcpy(idx->checksum, data + trailer_offset, checksum_size);
 
-	if (git_hash_buf(idx_checksum.id, data, (size_t)trailer_offset, GIT_HASH_ALGORITHM_SHA1) < 0)
+	if (git_hash_buf(checksum, data, (size_t)trailer_offset, GIT_HASH_ALGORITHM_SHA1) < 0)
 		return midx_error("could not calculate signature");
-	if (!git_oid_equal(&idx_checksum, &idx->checksum))
+	if (memcmp(checksum, idx->checksum, checksum_size) != 0)
 		return midx_error("index signature mismatch");
 
 	chunk_hdr = data + sizeof(struct git_midx_header);
@@ -341,7 +345,8 @@ bool git_midx_needs_refresh(
 	git_file fd = -1;
 	struct stat st;
 	ssize_t bytes_read;
-	git_oid idx_checksum = {{0}};
+	unsigned char checksum[GIT_HASH_SHA1_SIZE];
+	size_t checksum_size;
 
 	/* TODO: properly open the file without access time using O_NOATIME */
 	fd = git_futils_open_ro(path);
@@ -360,13 +365,14 @@ bool git_midx_needs_refresh(
 		return true;
 	}
 
-	bytes_read = p_pread(fd, &idx_checksum, GIT_OID_RAWSZ, st.st_size - GIT_OID_RAWSZ);
+	checksum_size = GIT_HASH_SHA1_SIZE;
+	bytes_read = p_pread(fd, checksum, checksum_size, st.st_size - GIT_OID_RAWSZ);
 	p_close(fd);
 
-	if (bytes_read != GIT_OID_RAWSZ)
+	if (bytes_read != (ssize_t)checksum_size)
 		return true;
 
-	return !git_oid_equal(&idx_checksum, &idx->checksum);
+	return (memcmp(checksum, idx->checksum, checksum_size) != 0);
 }
 
 int git_midx_entry_find(
@@ -653,7 +659,8 @@ static int midx_write(
 		oid_lookup = GIT_STR_INIT,
 		object_offsets = GIT_STR_INIT,
 		object_large_offsets = GIT_STR_INIT;
-	git_oid idx_checksum = {{0}};
+	unsigned char checksum[GIT_HASH_SHA1_SIZE];
+	size_t checksum_size;
 	git_midx_entry *entry;
 	object_entry_array_t object_entries_array = GIT_ARRAY_INIT;
 	git_vector object_entries = GIT_VECTOR_INIT;
@@ -669,6 +676,7 @@ static int midx_write(
 	hash_cb_data.cb_data = cb_data;
 	hash_cb_data.ctx = &ctx;
 
+	checksum_size = GIT_HASH_SHA1_SIZE;
 	error = git_hash_ctx_init(&ctx, GIT_HASH_ALGORITHM_SHA1);
 	if (error < 0)
 		return error;
@@ -820,10 +828,10 @@ static int midx_write(
 		goto cleanup;
 
 	/* Finalize the checksum and write the trailer. */
-	error = git_hash_final(idx_checksum.id, &ctx);
+	error = git_hash_final(checksum, &ctx);
 	if (error < 0)
 		goto cleanup;
-	error = write_cb((const char *)&idx_checksum, sizeof(idx_checksum), cb_data);
+	error = write_cb((char *)checksum, checksum_size, cb_data);
 	if (error < 0)
 		goto cleanup;
 

src/midx.h

@@ -51,7 +51,7 @@ typedef struct git_midx_file {
 	size_t num_object_large_offsets;
 
 	/* The trailer of the file. Contains the SHA1-checksum of the whole file. */
-	git_oid checksum;
+	unsigned char checksum[GIT_HASH_SHA1_SIZE];
 
 	/* something like ".git/objects/pack/multi-pack-index". */
 	git_str filename;

src/pack-objects.c

@@ -1422,7 +1422,12 @@ int git_packbuilder_write(
 	if ((error = git_indexer_commit(indexer, &stats)) < 0)
 		goto cleanup;
 
+#ifndef GIT_DEPRECATE_HARD
 	git_oid_cpy(&pb->pack_oid, git_indexer_hash(indexer));
+#endif
+
+	pb->pack_name = git__strdup(git_indexer_name(indexer));
+	GIT_ERROR_CHECK_ALLOC(pb->pack_name);
 
 cleanup:
 	git_indexer_free(indexer);
@@ -1432,10 +1437,17 @@ cleanup:
 
 #undef PREPARE_PACK
 
+#ifndef GIT_DEPRECATE_HARD
 const git_oid *git_packbuilder_hash(git_packbuilder *pb)
 {
 	return &pb->pack_oid;
 }
+#endif
+
+const char *git_packbuilder_name(git_packbuilder *pb)
+{
+	return pb->pack_name;
+}
 
 
 static int cb_tree_walk(
@@ -1803,5 +1815,7 @@ void git_packbuilder_free(git_packbuilder *pb)
 	git_hash_ctx_cleanup(&pb->ctx);
 	git_zstream_free(&pb->zstream);
 
+	git__free(pb->pack_name);
+
 	git__free(pb);
 }

src/pack-objects.h

@@ -73,7 +73,10 @@ struct git_packbuilder {
 	git_oidmap *walk_objects;
 	git_pool object_pool;
 
+#ifndef GIT_DEPRECATE_HARD
 	git_oid pack_oid; /* hash of written pack */
+#endif
+	char *pack_name; /* name of written pack */
 
 	/* synchronization objects */
 	git_mutex cache_mutex;

src/reset.c

@@ -188,7 +188,10 @@ int git_reset(
 	git_reset_t reset_type,
 	const git_checkout_options *checkout_opts)
 {
-	return reset(repo, target, git_oid_tostr_s(git_object_id(target)), reset_type, checkout_opts);
+	char to[GIT_OID_HEXSZ + 1];
+
+	git_oid_tostr(to, GIT_OID_HEXSZ + 1, git_object_id(target));
+	return reset(repo, target, to, reset_type, checkout_opts);
 }
 
 int git_reset_from_annotated(

tests/checkout/crlf.c

@@ -239,10 +239,10 @@ void test_checkout_crlf__autocrlf_false_index_size_is_unfiltered_size(void)
 
 	cl_repo_set_bool(g_repo, "core.autocrlf", false);
 
-	git_repository_index(&index, g_repo);
+	cl_git_pass(git_repository_index(&index, g_repo));
 	tick_index(index);
 
-	git_checkout_head(g_repo, &opts);
+	cl_git_pass(git_checkout_head(g_repo, &opts));
 
 	cl_assert((entry = git_index_get_bypath(index, "all-lf", 0)) != NULL);
 	cl_assert(entry->file_size == strlen(ALL_LF_TEXT_RAW));

tests/diff/workdir.c

 #include "clar_libgit2.h"
 #include "diff_helpers.h"
 #include "repository.h"
+#include "index.h"
 #include "git2/sys/diff.h"
 #include "../checkout/checkout_helpers.h"
 
@@ -2004,7 +2005,9 @@ void test_diff_workdir__only_writes_index_when_necessary(void)
 	git_diff *diff = NULL;
 	git_reference *head;
 	git_object *head_object;
-	git_oid initial, first, second;
+	unsigned char initial[GIT_HASH_SHA1_SIZE],
+	              first[GIT_HASH_SHA1_SIZE],
+	              second[GIT_HASH_SHA1_SIZE];
 	git_str path = GIT_STR_INIT;
 	struct stat st;
 	struct p_timeval times[2];
@@ -2019,7 +2022,7 @@ void test_diff_workdir__only_writes_index_when_necessary(void)
 
 	cl_git_pass(git_reset(g_repo, head_object, GIT_RESET_HARD, NULL));
 
-	git_oid_cpy(&initial, git_index_checksum(index));
+	memcpy(initial, git_index__checksum(index), GIT_HASH_SHA1_SIZE);
 
 	/* update the index timestamp to avoid raciness */
 	cl_must_pass(p_stat("status/.git/index", &st));
@@ -2035,8 +2038,8 @@ void test_diff_workdir__only_writes_index_when_necessary(void)
 	cl_git_pass(git_diff_index_to_workdir(&diff, g_repo, NULL, &opts));
 	git_diff_free(diff);
 
-	git_oid_cpy(&first, git_index_checksum(index));
-	cl_assert(!git_oid_equal(&initial, &first));
+	memcpy(first, git_index__checksum(index), GIT_HASH_SHA1_SIZE);
+	cl_assert(memcmp(initial, first, GIT_HASH_SHA1_SIZE) != 0);
 
 	/* touch all the files so stat times are different */
 	cl_git_pass(git_str_sets(&path, "status"));
@@ -2046,8 +2049,8 @@ void test_diff_workdir__only_writes_index_when_necessary(void)
 	git_diff_free(diff);
 
 	/* ensure the second diff did update the index */
-	git_oid_cpy(&second, git_index_checksum(index));
-	cl_assert(!git_oid_equal(&first, &second));
+	memcpy(second, git_index__checksum(index), GIT_HASH_SHA1_SIZE);
+	cl_assert(memcmp(first, second, GIT_HASH_SHA1_SIZE) != 0);
 
 	git_str_dispose(&path);
 	git_object_free(head_object);

tests/graph/commit_graph.c → tests/graph/commitgraph.c

@@ -6,7 +6,7 @@
 #include "commit_graph.h"
 #include "futils.h"
 
-void test_graph_commit_graph__parse(void)
+void test_graph_commitgraph__parse(void)
 {
 	git_repository *repo;
 	struct git_commit_graph_file *file;
@@ -50,7 +50,7 @@ void test_graph_commit_graph__parse(void)
 	git_str_dispose(&commit_graph_path);
 }
 
-void test_graph_commit_graph__parse_octopus_merge(void)
+void test_graph_commitgraph__parse_octopus_merge(void)
 {
 	git_repository *repo;
 	struct git_commit_graph_file *file;
@@ -91,7 +91,7 @@ void test_graph_commit_graph__parse_octopus_merge(void)
 	git_str_dispose(&commit_graph_path);
 }
 
-void test_graph_commit_graph__writer(void)
+void test_graph_commitgraph__writer(void)
 {
 	git_repository *repo;
 	git_commit_graph_writer *w = NULL;

tests/pack/indexer.c

@@ -169,8 +169,7 @@ void test_pack_indexer__fix_thin(void)
 	cl_assert_equal_i(stats.indexed_objects, 2);
 	cl_assert_equal_i(stats.local_objects, 1);
 
-	git_oid_fromstr(&should_id, "fefdb2d740a3a6b6c03a0c7d6ce431c6d5810e13");
-	cl_assert_equal_oid(&should_id, git_indexer_hash(idx));
+	cl_assert_equal_s("fefdb2d740a3a6b6c03a0c7d6ce431c6d5810e13", git_indexer_name(idx));
 
 	git_indexer_free(idx);
 	git_odb_free(odb);

tests/pack/packbuilder.c

@@ -5,6 +5,7 @@
 #include "iterator.h"
 #include "vector.h"
 #include "posix.h"
+#include "hash.h"
 
 static git_repository *_repo;
 static git_revwalk *_revwalker;
@@ -98,8 +99,8 @@ void test_pack_packbuilder__create_pack(void)
 	git_indexer_progress stats;
 	git_str buf = GIT_STR_INIT, path = GIT_STR_INIT;
 	git_hash_ctx ctx;
-	git_oid hash;
-	char hex[GIT_OID_HEXSZ+1]; hex[GIT_OID_HEXSZ] = '\0';
+	unsigned char hash[GIT_HASH_SHA1_SIZE];
+	char hex[(GIT_HASH_SHA1_SIZE * 2) + 1];
 
 	seed_packbuilder();
 
@@ -107,8 +108,7 @@ void test_pack_packbuilder__create_pack(void)
 	cl_git_pass(git_packbuilder_foreach(_packbuilder, feed_indexer, &stats));
 	cl_git_pass(git_indexer_commit(_indexer, &stats));
 
-	git_oid_fmt(hex, git_indexer_hash(_indexer));
-	git_str_printf(&path, "pack-%s.pack", hex);
+	git_str_printf(&path, "pack-%s.pack", git_indexer_name(_indexer));
 
 	/*
 	 * By default, packfiles are created with only one thread.
@@ -128,27 +128,22 @@ void test_pack_packbuilder__create_pack(void)
 
 	cl_git_pass(git_hash_ctx_init(&ctx, GIT_HASH_ALGORITHM_SHA1));
 	cl_git_pass(git_hash_update(&ctx, buf.ptr, buf.size));
-	cl_git_pass(git_hash_final(hash.id, &ctx));
+	cl_git_pass(git_hash_final(hash, &ctx));
 	git_hash_ctx_cleanup(&ctx);
 
 	git_str_dispose(&path);
 	git_str_dispose(&buf);
 
-	git_oid_fmt(hex, &hash);
-
+	git_hash_fmt(hex, hash, GIT_HASH_SHA1_SIZE);
 	cl_assert_equal_s(hex, "5d410bdf97cf896f9007681b92868471d636954b");
 }
 
-void test_pack_packbuilder__get_hash(void)
+void test_pack_packbuilder__get_name(void)
 {
-	char hex[GIT_OID_HEXSZ+1]; hex[GIT_OID_HEXSZ] = '\0';
-
 	seed_packbuilder();
 
 	cl_git_pass(git_packbuilder_write(_packbuilder, ".", 0, NULL, NULL));
-	git_oid_fmt(hex, git_packbuilder_hash(_packbuilder));
-
-	cl_assert_equal_s(hex, "7f5fa362c664d68ba7221259be1cbd187434b2f0");
+	cl_assert_equal_s("7f5fa362c664d68ba7221259be1cbd187434b2f0", git_packbuilder_name(_packbuilder));
 }
 
 void test_pack_packbuilder__write_default_path(void)