Merge remote-tracking branch 'carlosmn/indexer-stream' into new-error-handling

examples/network/index-pack.c

@@ -12,6 +12,61 @@ int index_cb(const git_indexer_stats *stats, void *data)
 }
 
 int index_pack(git_repository *repo, int argc, char **argv)
+{
+  git_indexer_stream *idx;
+  git_indexer_stats stats = {0, 0};
+  int error, fd;
+  char hash[GIT_OID_HEXSZ + 1] = {0};
+  ssize_t read_bytes;
+  char buf[512];
+
+  if (argc < 2) {
+	  fprintf(stderr, "I need a packfile\n");
+	  return EXIT_FAILURE;
+  }
+
+  if (git_indexer_stream_new(&idx, ".git") < 0) {
+	  puts("bad idx");
+	  return -1;
+  }
+
+  if ((fd = open(argv[1], 0)) < 0) {
+	  perror("open");
+	  return -1;
+  }
+
+  do {
+	  read_bytes = read(fd, buf, sizeof(buf));
+	  if (read_bytes < 0)
+		  break;
+
+	  if ((error = git_indexer_stream_add(idx, buf, read_bytes, &stats)) < 0)
+		  goto cleanup;
+
+	  printf("\rIndexing %d of %d", stats.processed, stats.total);
+  } while (read_bytes > 0);
+
+  if (read_bytes < 0) {
+	  error = -1;
+	  perror("failed reading");
+	  goto cleanup;
+  }
+
+  if ((error = git_indexer_stream_finalize(idx, &stats)) < 0)
+	  goto cleanup;
+
+  printf("\rIndexing %d of %d\n", stats.processed, stats.total);
+
+  git_oid_fmt(hash, git_indexer_stream_hash(idx));
+  puts(hash);
+
+cleanup:
+  close(fd);
+  git_indexer_stream_free(idx);
+  return error;
+}
+
+int index_pack_old(git_repository *repo, int argc, char **argv)
 {
   git_indexer *indexer;
   git_indexer_stats stats;

include/git2/indexer.h

@@ -23,6 +23,51 @@ typedef struct git_indexer_stats {
 
 
 typedef struct git_indexer git_indexer;
+typedef struct git_indexer_stream git_indexer_stream;
+
+/**
+ * Create a new streaming indexer instance
+ *
+ * @param out where to store the inexer instance
+ * @param path to the gitdir (metadata directory)
+ */
+GIT_EXTERN(int) git_indexer_stream_new(git_indexer_stream **out, const char *gitdir);
+
+/**
+ * Add data to the indexer
+ *
+ * @param idx the indexer
+ * @param data the data to add
+ * @param size the size of the data
+ * @param stats stat storage
+ */
+GIT_EXTERN(int) git_indexer_stream_add(git_indexer_stream *idx, void *data, size_t size, git_indexer_stats *stats);
+
+/**
+ * Finalize the pack and index
+ *
+ * Resolve any pending deltas and write out the index file
+ *
+ * @param idx the indexer
+ */
+GIT_EXTERN(int) git_indexer_stream_finalize(git_indexer_stream *idx, git_indexer_stats *stats);
+
+/**
+ * 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.
+ *
+ * @param idx the indexer instance
+ */
+GIT_EXTERN(const git_oid *) git_indexer_stream_hash(git_indexer_stream *idx);
+
+/**
+ * Free the indexer and its resources
+ *
+ * @param idx the indexer to free
+ */
+GIT_EXTERN(void) git_indexer_stream_free(git_indexer_stream *idx);
 
 /**
  * Create a new indexer instance

src/filebuf.c

@@ -194,14 +194,19 @@ int git_filebuf_open(git_filebuf *file, const char *path, int flags)
 
 	memset(file, 0x0, sizeof(git_filebuf));
 
+	if (flags & GIT_FILEBUF_DO_NOT_BUFFER)
+		file->do_not_buffer = true;
+
 	file->buf_size = WRITE_BUFFER_SIZE;
 	file->buf_pos = 0;
 	file->fd = -1;
 	file->last_error = BUFERR_OK;
 
 	/* Allocate the main cache buffer */
+	if (!file->do_not_buffer) {
 		file->buffer = git__malloc(file->buf_size);
 		GITERR_CHECK_ALLOC(file->buffer);
+	}
 
 	/* If we are hashing on-write, allocate a new hash context */
 	if (flags & GIT_FILEBUF_HASH_CONTENTS) {
@@ -345,6 +350,9 @@ int git_filebuf_write(git_filebuf *file, const void *buff, size_t len)
 
 	ENSURE_BUF_OK(file);
 
+	if (file->do_not_buffer)
+		return file->write(file, (void *)buff, len);
+
 	for (;;) {
 		size_t space_left = file->buf_size - file->buf_pos;
 

src/filebuf.h

@@ -19,7 +19,8 @@
 #define GIT_FILEBUF_APPEND				(1 << 2)
 #define GIT_FILEBUF_FORCE				(1 << 3)
 #define GIT_FILEBUF_TEMPORARY			(1 << 4)
-#define GIT_FILEBUF_DEFLATE_SHIFT		(5)
+#define GIT_FILEBUF_DO_NOT_BUFFER		(1 << 5)
+#define GIT_FILEBUF_DEFLATE_SHIFT		(6)
 
 #define GIT_FILELOCK_EXTENSION ".lock\0"
 #define GIT_FILELOCK_EXTLENGTH 6
@@ -41,6 +42,7 @@ struct git_filebuf {
 	size_t buf_size, buf_pos;
 	git_file fd;
 	bool fd_is_open;
+	bool do_not_buffer;
 	int last_error;
 };
 

src/indexer.c

@@ -30,8 +30,6 @@ struct entry {
 
 struct git_indexer {
 	struct git_pack_file *pack;
-	struct stat st;
-	struct git_pack_header hdr;
 	size_t nr_objects;
 	git_vector objects;
 	git_filebuf file;
@@ -39,27 +37,84 @@ struct git_indexer {
 	git_oid hash;
 };
 
+struct git_indexer_stream {
+	unsigned int parsed_header :1,
+		opened_pack;
+	struct git_pack_file *pack;
+	git_filebuf pack_file;
+	git_filebuf index_file;
+	git_off_t off;
+	size_t nr_objects;
+	git_vector objects;
+	git_vector deltas;
+	unsigned int fanout[256];
+	git_oid hash;
+};
+
+struct delta_info {
+	git_off_t delta_off;
+};
+
 const git_oid *git_indexer_hash(git_indexer *idx)
 {
 	return &idx->hash;
 }
 
-static int parse_header(git_indexer *idx)
+const git_oid *git_indexer_stream_hash(git_indexer_stream *idx)
+{
+	return &idx->hash;
+}
+
+static int open_pack(struct git_pack_file **out, const char *filename)
+{
+	size_t namelen;
+	struct git_pack_file *pack;
+	struct stat st;
+	int fd;
+
+	namelen = strlen(filename);
+	pack = git__calloc(1, sizeof(struct git_pack_file) + namelen + 1);
+	GITERR_CHECK_ALLOC(pack);
+
+	memcpy(pack->pack_name, filename, namelen + 1);
+
+	if (p_stat(filename, &st) < 0) {
+		giterr_set(GITERR_OS, "Failed to stat packfile.");
+		goto cleanup;
+	}
+
+	if ((fd = p_open(pack->pack_name, O_RDONLY)) < 0) {
+		giterr_set(GITERR_OS, "Failed to open packfile.");
+		goto cleanup;
+	}
+
+	pack->mwf.fd = fd;
+	pack->mwf.size = (git_off_t)st.st_size;
+
+	*out = pack;
+	return 0;
+
+cleanup:
+	git__free(pack);
+	return -1;
+}
+
+static int parse_header(struct git_pack_header *hdr, struct git_pack_file *pack)
 {
 	int error;
 
 	/* Verify we recognize this pack file format. */
-	if ((error = p_read(idx->pack->mwf.fd, &idx->hdr, sizeof(idx->hdr))) < 0) {
+	if ((error = p_read(pack->mwf.fd, hdr, sizeof(*hdr))) < 0) {
 		giterr_set(GITERR_OS, "Failed to read in pack header");
 		return error;
 	}
 
-	if (idx->hdr.hdr_signature != ntohl(PACK_SIGNATURE)) {
+	if (hdr->hdr_signature != ntohl(PACK_SIGNATURE)) {
 		giterr_set(GITERR_INVALID, "Wrong pack signature");
 		return -1;
 	}
 
-	if (!pack_version_ok(idx->hdr.hdr_version)) {
+	if (!pack_version_ok(hdr->hdr_version)) {
 		giterr_set(GITERR_INVALID, "Wrong pack version");
 		return -1;
 	}
@@ -83,12 +138,446 @@ static int cache_cmp(const void *a, const void *b)
 	return git_oid_cmp(&ea->sha1, &eb->sha1);
 }
 
+int git_indexer_stream_new(git_indexer_stream **out, const char *prefix)
+{
+	git_indexer_stream *idx;
+	git_buf path = GIT_BUF_INIT;
+	static const char suff[] = "/objects/pack/pack-received";
+	int error;
+
+	idx = git__calloc(1, sizeof(git_indexer_stream));
+	GITERR_CHECK_ALLOC(idx);
+
+	error = git_buf_joinpath(&path, prefix, suff);
+	if (error < 0)
+		goto cleanup;
+
+	error = git_filebuf_open(&idx->pack_file, path.ptr,
+				 GIT_FILEBUF_TEMPORARY | GIT_FILEBUF_DO_NOT_BUFFER);
+	git_buf_free(&path);
+	if (error < 0)
+		goto cleanup;
+
+	*out = idx;
+	return 0;
+
+cleanup:
+	git_buf_free(&path);
+	git_filebuf_cleanup(&idx->pack_file);
+	git__free(idx);
+	return -1;
+}
+
+/* Try to store the delta so we can try to resolve it later */
+static int store_delta(git_indexer_stream *idx)
+{
+	git_otype type;
+	git_mwindow *w = NULL;
+	git_mwindow_file *mwf = &idx->pack->mwf;
+	git_off_t entry_start = idx->off;
+	struct delta_info *delta;
+	size_t entry_size;
+	git_rawobj obj;
+	int error;
+
+	/*
+	 * ref-delta objects can refer to object that we haven't
+	 * found yet, so give it another opportunity
+	 */
+	if (git_packfile_unpack_header(&entry_size, &type, mwf, &w, &idx->off) < 0)
+		return -1;
+
+	git_mwindow_close(&w);
+
+	/* If it's not a delta, mark it as failure, we can't do anything with it */
+	if (type != GIT_OBJ_REF_DELTA && type != GIT_OBJ_OFS_DELTA)
+		return -1;
+
+	if (type == GIT_OBJ_REF_DELTA) {
+		idx->off += GIT_OID_RAWSZ;
+	} else {
+		git_off_t base_off;
+
+		base_off = get_delta_base(idx->pack, &w, &idx->off, type, entry_start);
+		git_mwindow_close(&w);
+		if (base_off < 0)
+			return (int)base_off;
+	}
+
+	error = packfile_unpack_compressed(&obj, idx->pack, &w, &idx->off, entry_size, type);
+	if (error == GIT_ESHORTBUFFER) {
+		idx->off = entry_start;
+		return GIT_ESHORTBUFFER;
+	} else if (error < 0){
+		return -1;
+	}
+
+	delta = git__calloc(1, sizeof(struct delta_info));
+	GITERR_CHECK_ALLOC(delta);
+	delta->delta_off = entry_start;
+
+	git__free(obj.data);
+
+	if (git_vector_insert(&idx->deltas, delta) < 0)
+		return -1;
+
+	return 0;
+}
+
+static int hash_and_save(git_indexer_stream *idx, git_rawobj *obj, git_off_t entry_start)
+{
+	int i;
+	git_oid oid;
+	void *packed;
+	size_t entry_size;
+	unsigned int left;
+	struct entry *entry;
+	git_mwindow *w = NULL;
+	git_mwindow_file *mwf = &idx->pack->mwf;
+	struct git_pack_entry *pentry;
+
+	entry = git__calloc(1, sizeof(*entry));
+	GITERR_CHECK_ALLOC(entry);
+
+	if (entry_start > UINT31_MAX) {
+		entry->offset = UINT32_MAX;
+		entry->offset_long = entry_start;
+	} else {
+		entry->offset = (uint32_t)entry_start;
+	}
+
+	/* FIXME: Parse the object instead of hashing it */
+	if (git_odb__hashobj(&oid, obj) < 0) {
+		giterr_set(GITERR_INVALID, "Failed to hash object");
+		return -1;
+	}
+
+	pentry = git__malloc(sizeof(struct git_pack_entry));
+	GITERR_CHECK_ALLOC(pentry);
+
+	git_oid_cpy(&pentry->sha1, &oid);
+	pentry->offset = entry_start;
+	if (git_vector_insert(&idx->pack->cache, pentry) < 0)
+		goto on_error;
+
+	git_oid_cpy(&entry->oid, &oid);
+	entry->crc = crc32(0L, Z_NULL, 0);
+
+	entry_size = (size_t)(idx->off - entry_start);
+	packed = git_mwindow_open(mwf, &w, entry_start, entry_size, &left);
+	if (packed == NULL)
+		goto on_error;
+
+	entry->crc = htonl(crc32(entry->crc, packed, (uInt)entry_size));
+	git_mwindow_close(&w);
+
+	/* Add the object to the list */
+	if (git_vector_insert(&idx->objects, entry) < 0)
+		goto on_error;
+
+	for (i = oid.id[0]; i < 256; ++i) {
+		idx->fanout[i]++;
+	}
+
+	return 0;
+
+on_error:
+	git__free(entry);
+	git__free(pentry);
+	git__free(obj->data);
+	return -1;
+}
+
+int git_indexer_stream_add(git_indexer_stream *idx, void *data, size_t size, git_indexer_stats *stats)
+{
+	int error;
+	struct git_pack_header hdr;
+	size_t processed = stats->processed;
+	git_mwindow_file *mwf = &idx->pack->mwf;
+
+	assert(idx && data && stats);
+
+	if (git_filebuf_write(&idx->pack_file, data, size) < 0)
+		return -1;
+
+	/* Make sure we set the new size of the pack */
+	if (idx->opened_pack) {
+		idx->pack->mwf.size += size;
+		//printf("\nadding %zu for %zu\n", size, idx->pack->mwf.size);
+	} else {
+		if (open_pack(&idx->pack, idx->pack_file.path_lock) < 0)
+			return -1;
+		idx->opened_pack = 1;
+		mwf = &idx->pack->mwf;
+		if (git_mwindow_file_register(&idx->pack->mwf) < 0)
+			return -1;
+
+		return 0;
+	}
+
+	if (!idx->parsed_header) {
+		if ((unsigned)idx->pack->mwf.size < sizeof(hdr))
+			return 0;
+
+		if (parse_header(&hdr, idx->pack) < 0)
+			return -1;
+
+		idx->parsed_header = 1;
+		idx->nr_objects = ntohl(hdr.hdr_entries);
+		idx->off = sizeof(struct git_pack_header);
+
+		/* for now, limit to 2^32 objects */
+		assert(idx->nr_objects == (size_t)((unsigned int)idx->nr_objects));
+
+		if (git_vector_init(&idx->pack->cache, (unsigned int)idx->nr_objects, cache_cmp) < 0)
+			return -1;
+
+		idx->pack->has_cache = 1;
+		if (git_vector_init(&idx->objects, (unsigned int)idx->nr_objects, objects_cmp) < 0)
+			return -1;
+
+		if (git_vector_init(&idx->deltas, (unsigned int)(idx->nr_objects / 2), NULL) < 0)
+			return -1;
+
+		stats->total = (unsigned int)idx->nr_objects;
+		stats->processed = 0;
+	}
+
+	/* Now that we have data in the pack, let's try to parse it */
+
+	/* As the file grows any windows we try to use will be out of date */
+	git_mwindow_free_all(mwf);
+	while (processed < idx->nr_objects) {
+		git_rawobj obj;
+		git_off_t entry_start = idx->off;
+
+		if (idx->pack->mwf.size <= idx->off + 20)
+			return 0;
+
+		error = git_packfile_unpack(&obj, idx->pack, &idx->off);
+		if (error == GIT_ESHORTBUFFER) {
+			idx->off = entry_start;
+			return 0;
+		}
+
+		if (error < 0) {
+			idx->off = entry_start;
+			error = store_delta(idx);
+			if (error == GIT_ESHORTBUFFER)
+				return 0;
+			if (error < 0)
+				return error;
+
+			continue;
+		}
+
+		if (hash_and_save(idx, &obj, entry_start) < 0)
+			goto on_error;
+
+		git__free(obj.data);
+
+		stats->processed = ++processed;
+	}
+
+	return 0;
+
+on_error:
+	git_mwindow_free_all(mwf);
+	return -1;
+}
+
+static int index_path_stream(git_buf *path, git_indexer_stream *idx, const char *suffix)
+{
+	const char prefix[] = "pack-";
+	size_t slash = (size_t)path->size;
+
+	/* search backwards for '/' */
+	while (slash > 0 && path->ptr[slash - 1] != '/')
+		slash--;
+
+	if (git_buf_grow(path, slash + 1 + strlen(prefix) +
+					 GIT_OID_HEXSZ + strlen(suffix) + 1) < 0)
+		return -1;
+
+	git_buf_truncate(path, slash);
+	git_buf_puts(path, prefix);
+	git_oid_fmt(path->ptr + path->size, &idx->hash);
+	path->size += GIT_OID_HEXSZ;
+	git_buf_puts(path, suffix);
+
+	return git_buf_oom(path) ? -1 : 0;
+}
+
+static int resolve_deltas(git_indexer_stream *idx, git_indexer_stats *stats)
+{
+	unsigned int i;
+	struct delta_info *delta;
+
+	git_vector_foreach(&idx->deltas, i, delta) {
+		git_rawobj obj;
+
+		idx->off = delta->delta_off;
+		if (git_packfile_unpack(&obj, idx->pack, &idx->off) < 0)
+			return -1;
+
+		if (hash_and_save(idx, &obj, delta->delta_off) < 0)
+			return -1;
+
+		git__free(obj.data);
+		stats->processed++;
+	}
+
+	return 0;
+}
+
+int git_indexer_stream_finalize(git_indexer_stream *idx, git_indexer_stats *stats)
+{
+	git_mwindow *w = NULL;
+	unsigned int i, long_offsets = 0, left;
+	struct git_pack_idx_header hdr;
+	git_buf filename = GIT_BUF_INIT;
+	struct entry *entry;
+	void *packfile_hash;
+	git_oid file_hash;
+	SHA_CTX ctx;
+
+	if (idx->deltas.length > 0)
+		if (resolve_deltas(idx, stats) < 0)
+			return -1;
+
+	git_vector_sort(&idx->objects);
+
+	git_buf_sets(&filename, idx->pack->pack_name);
+	git_buf_truncate(&filename, filename.size - strlen("pack"));
+	git_buf_puts(&filename, "idx");
+	if (git_buf_oom(&filename))
+		return -1;
+
+	if (git_filebuf_open(&idx->index_file, filename.ptr, GIT_FILEBUF_HASH_CONTENTS) < 0)
+		goto on_error;
+
+	/* Write out the header */
+	hdr.idx_signature = htonl(PACK_IDX_SIGNATURE);
+	hdr.idx_version = htonl(2);
+	git_filebuf_write(&idx->index_file, &hdr, sizeof(hdr));
+
+	/* Write out the fanout table */
+	for (i = 0; i < 256; ++i) {
+		uint32_t n = htonl(idx->fanout[i]);
+		git_filebuf_write(&idx->index_file, &n, sizeof(n));
+	}
+
+	/* Write out the object names (SHA-1 hashes) */
+	SHA1_Init(&ctx);
+	git_vector_foreach(&idx->objects, i, entry) {
+		git_filebuf_write(&idx->index_file, &entry->oid, sizeof(git_oid));
+		SHA1_Update(&ctx, &entry->oid, GIT_OID_RAWSZ);
+	}
+	SHA1_Final(idx->hash.id, &ctx);
+
+	/* Write out the CRC32 values */
+	git_vector_foreach(&idx->objects, i, entry) {
+		git_filebuf_write(&idx->index_file, &entry->crc, sizeof(uint32_t));
+	}
+
+	/* Write out the offsets */
+	git_vector_foreach(&idx->objects, i, entry) {
+		uint32_t n;
+
+		if (entry->offset == UINT32_MAX)
+			n = htonl(0x80000000 | long_offsets++);
+		else
+			n = htonl(entry->offset);
+
+		git_filebuf_write(&idx->index_file, &n, sizeof(uint32_t));
+	}
+
+	/* Write out the long offsets */
+	git_vector_foreach(&idx->objects, i, entry) {
+		uint32_t split[2];
+
+		if (entry->offset != UINT32_MAX)
+			continue;
+
+		split[0] = htonl(entry->offset_long >> 32);
+		split[1] = htonl(entry->offset_long & 0xffffffff);
+
+		git_filebuf_write(&idx->index_file, &split, sizeof(uint32_t) * 2);
+	}
+
+	/* Write out the packfile trailer */
+	packfile_hash = git_mwindow_open(&idx->pack->mwf, &w, idx->pack->mwf.size - GIT_OID_RAWSZ, GIT_OID_RAWSZ, &left);
+	if (packfile_hash == NULL) {
+		git_mwindow_close(&w);
+		goto on_error;
+	}
+
+	memcpy(&file_hash, packfile_hash, GIT_OID_RAWSZ);
+	git_mwindow_close(&w);
+
+	git_filebuf_write(&idx->index_file, &file_hash, sizeof(git_oid));
+
+	/* Write out the packfile trailer to the idx file as well */
+	if (git_filebuf_hash(&file_hash, &idx->index_file) < 0)
+		goto on_error;
+
+	git_filebuf_write(&idx->index_file, &file_hash, sizeof(git_oid));
+
+	/* Figure out what the final name should be */
+	if (index_path_stream(&filename, idx, ".idx") < 0)
+		goto on_error;
+
+	/* Commit file */
+	if (git_filebuf_commit_at(&idx->index_file, filename.ptr, GIT_PACK_FILE_MODE) < 0)
+		goto on_error;
+
+	git_mwindow_free_all(&idx->pack->mwf);
+
+	if (index_path_stream(&filename, idx, ".pack") < 0)
+		goto on_error;
+	/* And don't forget to rename the packfile to its new place. */
+	if (git_filebuf_commit_at(&idx->pack_file, filename.ptr, GIT_PACK_FILE_MODE) < 0)
+		return -1;
+
+	git_buf_free(&filename);
+	return 0;
+
+on_error:
+	git_mwindow_free_all(&idx->pack->mwf);
+	git_filebuf_cleanup(&idx->index_file);
+	git_buf_free(&filename);
+	return -1;
+}
+
+void git_indexer_stream_free(git_indexer_stream *idx)
+{
+	unsigned int i;
+	struct entry *e;
+	struct git_pack_entry *pe;
+	struct delta_info *delta;
+
+	if (idx == NULL)
+		return;
+
+	p_close(idx->pack->mwf.fd);
+	git_vector_foreach(&idx->objects, i, e)
+		git__free(e);
+	git_vector_free(&idx->objects);
+	git_vector_foreach(&idx->pack->cache, i, pe)
+		git__free(pe);
+	git_vector_free(&idx->pack->cache);
+	git_vector_foreach(&idx->deltas, i, delta)
+		git__free(delta);
+	git_vector_free(&idx->deltas);
+	git__free(idx->pack);
+	git__free(idx);
+}
 
 int git_indexer_new(git_indexer **out, const char *packname)
 {
 	git_indexer *idx;
-	size_t namelen;
+	struct git_pack_header hdr;
-	int ret, error;
+	int error;
 
 	assert(out && packname);
 
@@ -100,37 +589,12 @@ int git_indexer_new(git_indexer **out, const char *packname)
 	idx = git__calloc(1, sizeof(git_indexer));
 	GITERR_CHECK_ALLOC(idx);
 
-	namelen = strlen(packname);
+	open_pack(&idx->pack, packname);
-	idx->pack = git__calloc(1, sizeof(struct git_pack_file) + namelen + 1);
-	GITERR_CHECK_ALLOC(idx->pack);
 
-	memcpy(idx->pack->pack_name, packname, namelen + 1);
+	if ((error = parse_header(&hdr, idx->pack)) < 0)
-
-	if ((ret = p_stat(packname, &idx->st)) < 0) {
-		if (errno == ENOENT) {
-			giterr_set(GITERR_OS, "Failed to stat packfile. File not found");
-			error = GIT_ENOTFOUND;
-		} else {
-			giterr_set(GITERR_OS, "Failed to stat packfile.");
-			error = -1;
-		}
-
-		goto cleanup;
-	}
-
-	if ((ret = p_open(idx->pack->pack_name, O_RDONLY)) < 0) {
-		giterr_set(GITERR_OS, "Failed to open packfile.");
-		error = -1;
-		goto cleanup;
-	}
-
-	idx->pack->mwf.fd = ret;
-	idx->pack->mwf.size = (git_off_t)idx->st.st_size;
-
-	if ((error = parse_header(idx)) < 0)
 		goto cleanup;
 
-	idx->nr_objects = ntohl(idx->hdr.hdr_entries);
+	idx->nr_objects = ntohl(hdr.hdr_entries);
 
 	/* for now, limit to 2^32 objects */
 	assert(idx->nr_objects == (size_t)((unsigned int)idx->nr_objects));
@@ -151,7 +615,7 @@ int git_indexer_new(git_indexer **out, const char *packname)
 cleanup:
 	git_indexer_free(idx);
 
-	return error;
+	return -1;
 }
 
 static int index_path(git_buf *path, git_indexer *idx)
@@ -263,7 +727,7 @@ int git_indexer_write(git_indexer *idx)
 
 	/* Write out the packfile trailer */
 
-	packfile_hash = git_mwindow_open(&idx->pack->mwf, &w, idx->st.st_size - GIT_OID_RAWSZ, GIT_OID_RAWSZ, &left);
+	packfile_hash = git_mwindow_open(&idx->pack->mwf, &w, idx->pack->mwf.size - GIT_OID_RAWSZ, GIT_OID_RAWSZ, &left);
 	git_mwindow_close(&w);
 	if (packfile_hash == NULL) {
 		error = -1;
@@ -331,6 +795,7 @@ int git_indexer_run(git_indexer *idx, git_indexer_stats *stats)
 		git_off_t entry_start = off;
 		void *packed;
 		size_t entry_size;
+		char fmt[GIT_OID_HEXSZ] = {0};
 
 		entry = git__calloc(1, sizeof(*entry));
 		GITERR_CHECK_ALLOC(entry);
@@ -361,6 +826,8 @@ int git_indexer_run(git_indexer *idx, git_indexer_stats *stats)
 
 		git_oid_cpy(&pentry->sha1, &oid);
 		pentry->offset = entry_start;
+		git_oid_fmt(fmt, &oid);
+		printf("adding %s to cache\n", fmt);
 		error = git_vector_insert(&idx->pack->cache, pentry);
 		if (error < 0)
 			goto cleanup;

src/mwindow.c

@@ -89,6 +89,7 @@ void git_mwindow_scan_lru(
 {
 	git_mwindow *w, *w_l;
 
+	puts("LRU");
 	for (w_l = NULL, w = mwf->windows; w; w = w->next) {
 		if (!w->inuse_cnt) {
 			/*
@@ -210,15 +211,17 @@ unsigned char *git_mwindow_open(
 	git_mwindow_ctl *ctl = &GIT_GLOBAL->mem_ctl;
 	git_mwindow *w = *cursor;
 
+
 	if (!w || !git_mwindow_contains(w, offset + extra)) {
 		if (w) {
 			w->inuse_cnt--;
 		}
 
 		for (w = mwf->windows; w; w = w->next) {
-			if (git_mwindow_contains(w, offset + extra))
+			if (git_mwindow_contains(w, offset + extra)) {
 				break;
 			}
+		}
 
 		/*
 		 * If there isn't a suitable window, we need to create a new
@@ -246,6 +249,7 @@ unsigned char *git_mwindow_open(
 	if (left)
 		*left = (unsigned int)(w->window_map.len - offset);
 
+	fflush(stdout);
 	return (unsigned char *) w->window_map.data + offset;
 }
 

src/pack.c

@@ -200,7 +200,8 @@ static unsigned char *pack_window_open(
 	return git_mwindow_open(&p->mwf, w_cursor, offset, 20, left);
  }
 
-static unsigned long packfile_unpack_header1(
+static int packfile_unpack_header1(
+		unsigned long *usedp,
 		size_t *sizep,
 		git_otype *type,
 		const unsigned char *buf,
@@ -215,8 +216,13 @@ static unsigned long packfile_unpack_header1(
 	size = c & 15;
 	shift = 4;
 	while (c & 0x80) {
-		if (len <= used || bitsizeof(long) <= shift)
+		if (len <= used)
-			return 0;
+			return GIT_ESHORTBUFFER;
+
+		if (bitsizeof(long) <= shift) {
+			*usedp = 0;
+			return -1;
+		}
 
 		c = buf[used++];
 		size += (c & 0x7f) << shift;
@@ -224,7 +230,8 @@ static unsigned long packfile_unpack_header1(
 	}
 
 	*sizep = (size_t)size;
-	return used;
+	*usedp = used;
+	return 0;
 }
 
 int git_packfile_unpack_header(
@@ -237,6 +244,7 @@ int git_packfile_unpack_header(
 	unsigned char *base;
 	unsigned int left;
 	unsigned long used;
+	int ret;
 
 	/* pack_window_open() assures us we have [base, base + 20) available
 	 * as a range that we can look at at. (Its actually the hash
@@ -247,10 +255,13 @@ int git_packfile_unpack_header(
 //	base = pack_window_open(p, w_curs, *curpos, &left);
 	base = git_mwindow_open(mwf, w_curs, *curpos, 20, &left);
 	if (base == NULL)
-		return -1;
+		return GIT_ESHORTBUFFER;
 
-	used = packfile_unpack_header1(size_p, type_p, base, left);
+	ret = packfile_unpack_header1(&used, size_p, type_p, base, left);
-	if (used == 0)
+	git_mwindow_close(w_curs);
+	if (ret == GIT_ESHORTBUFFER)
+		return ret;
+	else if (ret < 0)
 		return packfile_error("header length is zero");
 
 	*curpos += used;
@@ -271,12 +282,12 @@ static int packfile_unpack_delta(
 	int error;
 
 	base_offset = get_delta_base(p, w_curs, curpos, delta_type, obj_offset);
+	git_mwindow_close(w_curs);
 	if (base_offset == 0)
 		return packfile_error("delta offset is zero");
 	if (base_offset < 0) /* must actually be an error code */
 		return (int)base_offset;
 
-	git_mwindow_close(w_curs);
 	error = git_packfile_unpack(&base, p, &base_offset);
 
 	/*
@@ -289,6 +300,7 @@ static int packfile_unpack_delta(
 		return error;
 
 	error = packfile_unpack_compressed(&delta, p, w_curs, curpos, delta_size, delta_type);
+	git_mwindow_close(w_curs);
 	if (error < 0) {
 		git__free(base.data);
 		return error;
@@ -327,6 +339,8 @@ int git_packfile_unpack(
 	obj->type = GIT_OBJ_BAD;
 
 	error = git_packfile_unpack_header(&size, &type, &p->mwf, &w_curs, &curpos);
+	git_mwindow_close(&w_curs);
+
 	if (error < 0)
 		return error;
 
@@ -352,8 +366,6 @@ int git_packfile_unpack(
 		break;
 	}
 
-	git_mwindow_close(&w_curs);
-
 	*obj_offset = curpos;
 	return error;
 }
@@ -381,6 +393,7 @@ int packfile_unpack_compressed(
 	if (st != Z_OK) {
 		git__free(buffer);
 		giterr_set(GITERR_ZLIB, "Failed to inflate packfile");
+
 		return -1;
 	}
 
@@ -388,10 +401,17 @@ int packfile_unpack_compressed(
 		in = pack_window_open(p, w_curs, *curpos, &stream.avail_in);
 		stream.next_in = in;
 		st = inflate(&stream, Z_FINISH);
+		git_mwindow_close(w_curs);
 
 		if (!stream.avail_out)
 			break; /* the payload is larger than it should be */
 
+		if (st == Z_BUF_ERROR && in == NULL) {
+			inflateEnd(&stream);
+			git__free(buffer);
+			return GIT_ESHORTBUFFER;
+		}
+
 		*curpos += stream.next_in - in;
 	} while (st == Z_OK || st == Z_BUF_ERROR);
 
@@ -420,10 +440,15 @@ git_off_t get_delta_base(
 	git_otype type,
 	git_off_t delta_obj_offset)
 {
-	unsigned char *base_info = pack_window_open(p, w_curs, *curpos, NULL);
+	unsigned int left = 0;
+	unsigned char *base_info;
 	git_off_t base_offset;
 	git_oid unused;
 
+	base_info = pack_window_open(p, w_curs, *curpos, &left);
+	/* Assumption: the only reason this would fail is because the file is too small */
+	if (base_info == NULL)
+		return GIT_ESHORTBUFFER;
 	/* pack_window_open() assured us we have [base_info, base_info + 20)
 	 * as a range that we can look at without walking off the
 	 * end of the mapped window. Its actually the hash size
@@ -435,6 +460,8 @@ git_off_t get_delta_base(
 		unsigned char c = base_info[used++];
 		base_offset = c & 127;
 		while (c & 128) {
+			if (left <= used)
+				return GIT_ESHORTBUFFER;
 			base_offset += 1;
 			if (!base_offset || MSB(base_offset, 7))
 				return 0; /* overflow */

src/pack.h

@@ -83,6 +83,13 @@ int git_packfile_unpack_header(
 		git_off_t *curpos);
 
 int git_packfile_unpack(git_rawobj *obj, struct git_pack_file *p, git_off_t *obj_offset);
+int packfile_unpack_compressed(
+	git_rawobj *obj,
+	struct git_pack_file *p,
+	git_mwindow **w_curs,
+	git_off_t *curpos,
+	size_t size,
+	git_otype type);
 
 git_off_t get_delta_base(struct git_pack_file *p, git_mwindow **w_curs,
 		git_off_t *curpos, git_otype type,