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-rw-r--r--builtin/index-pack.c1262
1 files changed, 1262 insertions, 0 deletions
diff --git a/builtin/index-pack.c b/builtin/index-pack.c
new file mode 100644
index 0000000..dd1c5c9
--- /dev/null
+++ b/builtin/index-pack.c
@@ -0,0 +1,1262 @@
+#include "builtin.h"
+#include "delta.h"
+#include "pack.h"
+#include "csum-file.h"
+#include "blob.h"
+#include "commit.h"
+#include "tag.h"
+#include "tree.h"
+#include "progress.h"
+#include "fsck.h"
+#include "exec_cmd.h"
+
+static const char index_pack_usage[] =
+"git index-pack [-v] [-o <index-file>] [--keep | --keep=<msg>] [--verify] [--strict] (<pack-file> | --stdin [--fix-thin] [<pack-file>])";
+
+struct object_entry {
+ struct pack_idx_entry idx;
+ unsigned long size;
+ unsigned int hdr_size;
+ enum object_type type;
+ enum object_type real_type;
+ unsigned delta_depth;
+ int base_object_no;
+};
+
+union delta_base {
+ unsigned char sha1[20];
+ off_t offset;
+};
+
+struct base_data {
+ struct base_data *base;
+ struct base_data *child;
+ struct object_entry *obj;
+ void *data;
+ unsigned long size;
+ int ref_first, ref_last;
+ int ofs_first, ofs_last;
+};
+
+/*
+ * Even if sizeof(union delta_base) == 24 on 64-bit archs, we really want
+ * to memcmp() only the first 20 bytes.
+ */
+#define UNION_BASE_SZ 20
+
+#define FLAG_LINK (1u<<20)
+#define FLAG_CHECKED (1u<<21)
+
+struct delta_entry {
+ union delta_base base;
+ int obj_no;
+};
+
+static struct object_entry *objects;
+static struct delta_entry *deltas;
+static struct base_data *base_cache;
+static size_t base_cache_used;
+static int nr_objects;
+static int nr_deltas;
+static int nr_resolved_deltas;
+
+static int from_stdin;
+static int strict;
+static int verbose;
+
+static struct progress *progress;
+
+/* We always read in 4kB chunks. */
+static unsigned char input_buffer[4096];
+static unsigned int input_offset, input_len;
+static off_t consumed_bytes;
+static unsigned deepest_delta;
+static git_SHA_CTX input_ctx;
+static uint32_t input_crc32;
+static int input_fd, output_fd, pack_fd;
+
+static int mark_link(struct object *obj, int type, void *data)
+{
+ if (!obj)
+ return -1;
+
+ if (type != OBJ_ANY && obj->type != type)
+ die("object type mismatch at %s", sha1_to_hex(obj->sha1));
+
+ obj->flags |= FLAG_LINK;
+ return 0;
+}
+
+/* The content of each linked object must have been checked
+ or it must be already present in the object database */
+static void check_object(struct object *obj)
+{
+ if (!obj)
+ return;
+
+ if (!(obj->flags & FLAG_LINK))
+ return;
+
+ if (!(obj->flags & FLAG_CHECKED)) {
+ unsigned long size;
+ int type = sha1_object_info(obj->sha1, &size);
+ if (type != obj->type || type <= 0)
+ die("object of unexpected type");
+ obj->flags |= FLAG_CHECKED;
+ return;
+ }
+}
+
+static void check_objects(void)
+{
+ unsigned i, max;
+
+ max = get_max_object_index();
+ for (i = 0; i < max; i++)
+ check_object(get_indexed_object(i));
+}
+
+
+/* Discard current buffer used content. */
+static void flush(void)
+{
+ if (input_offset) {
+ if (output_fd >= 0)
+ write_or_die(output_fd, input_buffer, input_offset);
+ git_SHA1_Update(&input_ctx, input_buffer, input_offset);
+ memmove(input_buffer, input_buffer + input_offset, input_len);
+ input_offset = 0;
+ }
+}
+
+/*
+ * Make sure at least "min" bytes are available in the buffer, and
+ * return the pointer to the buffer.
+ */
+static void *fill(int min)
+{
+ if (min <= input_len)
+ return input_buffer + input_offset;
+ if (min > sizeof(input_buffer))
+ die("cannot fill %d bytes", min);
+ flush();
+ do {
+ ssize_t ret = xread(input_fd, input_buffer + input_len,
+ sizeof(input_buffer) - input_len);
+ if (ret <= 0) {
+ if (!ret)
+ die("early EOF");
+ die_errno("read error on input");
+ }
+ input_len += ret;
+ if (from_stdin)
+ display_throughput(progress, consumed_bytes + input_len);
+ } while (input_len < min);
+ return input_buffer;
+}
+
+static void use(int bytes)
+{
+ if (bytes > input_len)
+ die("used more bytes than were available");
+ input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
+ input_len -= bytes;
+ input_offset += bytes;
+
+ /* make sure off_t is sufficiently large not to wrap */
+ if (signed_add_overflows(consumed_bytes, bytes))
+ die("pack too large for current definition of off_t");
+ consumed_bytes += bytes;
+}
+
+static const char *open_pack_file(const char *pack_name)
+{
+ if (from_stdin) {
+ input_fd = 0;
+ if (!pack_name) {
+ static char tmp_file[PATH_MAX];
+ output_fd = odb_mkstemp(tmp_file, sizeof(tmp_file),
+ "pack/tmp_pack_XXXXXX");
+ pack_name = xstrdup(tmp_file);
+ } else
+ output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
+ if (output_fd < 0)
+ die_errno("unable to create '%s'", pack_name);
+ pack_fd = output_fd;
+ } else {
+ input_fd = open(pack_name, O_RDONLY);
+ if (input_fd < 0)
+ die_errno("cannot open packfile '%s'", pack_name);
+ output_fd = -1;
+ pack_fd = input_fd;
+ }
+ git_SHA1_Init(&input_ctx);
+ return pack_name;
+}
+
+static void parse_pack_header(void)
+{
+ struct pack_header *hdr = fill(sizeof(struct pack_header));
+
+ /* Header consistency check */
+ if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
+ die("pack signature mismatch");
+ if (!pack_version_ok(hdr->hdr_version))
+ die("pack version %"PRIu32" unsupported",
+ ntohl(hdr->hdr_version));
+
+ nr_objects = ntohl(hdr->hdr_entries);
+ use(sizeof(struct pack_header));
+}
+
+static NORETURN void bad_object(unsigned long offset, const char *format,
+ ...) __attribute__((format (printf, 2, 3)));
+
+static NORETURN void bad_object(unsigned long offset, const char *format, ...)
+{
+ va_list params;
+ char buf[1024];
+
+ va_start(params, format);
+ vsnprintf(buf, sizeof(buf), format, params);
+ va_end(params);
+ die("pack has bad object at offset %lu: %s", offset, buf);
+}
+
+static struct base_data *alloc_base_data(void)
+{
+ struct base_data *base = xmalloc(sizeof(struct base_data));
+ memset(base, 0, sizeof(*base));
+ base->ref_last = -1;
+ base->ofs_last = -1;
+ return base;
+}
+
+static void free_base_data(struct base_data *c)
+{
+ if (c->data) {
+ free(c->data);
+ c->data = NULL;
+ base_cache_used -= c->size;
+ }
+}
+
+static void prune_base_data(struct base_data *retain)
+{
+ struct base_data *b;
+ for (b = base_cache;
+ base_cache_used > delta_base_cache_limit && b;
+ b = b->child) {
+ if (b->data && b != retain)
+ free_base_data(b);
+ }
+}
+
+static void link_base_data(struct base_data *base, struct base_data *c)
+{
+ if (base)
+ base->child = c;
+ else
+ base_cache = c;
+
+ c->base = base;
+ c->child = NULL;
+ if (c->data)
+ base_cache_used += c->size;
+ prune_base_data(c);
+}
+
+static void unlink_base_data(struct base_data *c)
+{
+ struct base_data *base = c->base;
+ if (base)
+ base->child = NULL;
+ else
+ base_cache = NULL;
+ free_base_data(c);
+}
+
+static void *unpack_entry_data(unsigned long offset, unsigned long size)
+{
+ int status;
+ git_zstream stream;
+ void *buf = xmalloc(size);
+
+ memset(&stream, 0, sizeof(stream));
+ git_inflate_init(&stream);
+ stream.next_out = buf;
+ stream.avail_out = size;
+
+ do {
+ stream.next_in = fill(1);
+ stream.avail_in = input_len;
+ status = git_inflate(&stream, 0);
+ use(input_len - stream.avail_in);
+ } while (status == Z_OK);
+ if (stream.total_out != size || status != Z_STREAM_END)
+ bad_object(offset, "inflate returned %d", status);
+ git_inflate_end(&stream);
+ return buf;
+}
+
+static void *unpack_raw_entry(struct object_entry *obj, union delta_base *delta_base)
+{
+ unsigned char *p;
+ unsigned long size, c;
+ off_t base_offset;
+ unsigned shift;
+ void *data;
+
+ obj->idx.offset = consumed_bytes;
+ input_crc32 = crc32(0, NULL, 0);
+
+ p = fill(1);
+ c = *p;
+ use(1);
+ obj->type = (c >> 4) & 7;
+ size = (c & 15);
+ shift = 4;
+ while (c & 0x80) {
+ p = fill(1);
+ c = *p;
+ use(1);
+ size += (c & 0x7f) << shift;
+ shift += 7;
+ }
+ obj->size = size;
+
+ switch (obj->type) {
+ case OBJ_REF_DELTA:
+ hashcpy(delta_base->sha1, fill(20));
+ use(20);
+ break;
+ case OBJ_OFS_DELTA:
+ memset(delta_base, 0, sizeof(*delta_base));
+ p = fill(1);
+ c = *p;
+ use(1);
+ base_offset = c & 127;
+ while (c & 128) {
+ base_offset += 1;
+ if (!base_offset || MSB(base_offset, 7))
+ bad_object(obj->idx.offset, "offset value overflow for delta base object");
+ p = fill(1);
+ c = *p;
+ use(1);
+ base_offset = (base_offset << 7) + (c & 127);
+ }
+ delta_base->offset = obj->idx.offset - base_offset;
+ if (delta_base->offset <= 0 || delta_base->offset >= obj->idx.offset)
+ bad_object(obj->idx.offset, "delta base offset is out of bound");
+ break;
+ case OBJ_COMMIT:
+ case OBJ_TREE:
+ case OBJ_BLOB:
+ case OBJ_TAG:
+ break;
+ default:
+ bad_object(obj->idx.offset, "unknown object type %d", obj->type);
+ }
+ obj->hdr_size = consumed_bytes - obj->idx.offset;
+
+ data = unpack_entry_data(obj->idx.offset, obj->size);
+ obj->idx.crc32 = input_crc32;
+ return data;
+}
+
+static void *get_data_from_pack(struct object_entry *obj)
+{
+ off_t from = obj[0].idx.offset + obj[0].hdr_size;
+ unsigned long len = obj[1].idx.offset - from;
+ unsigned char *data, *inbuf;
+ git_zstream stream;
+ int status;
+
+ data = xmalloc(obj->size);
+ inbuf = xmalloc((len < 64*1024) ? len : 64*1024);
+
+ memset(&stream, 0, sizeof(stream));
+ git_inflate_init(&stream);
+ stream.next_out = data;
+ stream.avail_out = obj->size;
+
+ do {
+ ssize_t n = (len < 64*1024) ? len : 64*1024;
+ n = pread(pack_fd, inbuf, n, from);
+ if (n < 0)
+ die_errno("cannot pread pack file");
+ if (!n)
+ die("premature end of pack file, %lu bytes missing", len);
+ from += n;
+ len -= n;
+ stream.next_in = inbuf;
+ stream.avail_in = n;
+ status = git_inflate(&stream, 0);
+ } while (len && status == Z_OK && !stream.avail_in);
+
+ /* This has been inflated OK when first encountered, so... */
+ if (status != Z_STREAM_END || stream.total_out != obj->size)
+ die("serious inflate inconsistency");
+
+ git_inflate_end(&stream);
+ free(inbuf);
+ return data;
+}
+
+static int compare_delta_bases(const union delta_base *base1,
+ const union delta_base *base2,
+ enum object_type type1,
+ enum object_type type2)
+{
+ int cmp = type1 - type2;
+ if (cmp)
+ return cmp;
+ return memcmp(base1, base2, UNION_BASE_SZ);
+}
+
+static int find_delta(const union delta_base *base, enum object_type type)
+{
+ int first = 0, last = nr_deltas;
+
+ while (first < last) {
+ int next = (first + last) / 2;
+ struct delta_entry *delta = &deltas[next];
+ int cmp;
+
+ cmp = compare_delta_bases(base, &delta->base,
+ type, objects[delta->obj_no].type);
+ if (!cmp)
+ return next;
+ if (cmp < 0) {
+ last = next;
+ continue;
+ }
+ first = next+1;
+ }
+ return -first-1;
+}
+
+static void find_delta_children(const union delta_base *base,
+ int *first_index, int *last_index,
+ enum object_type type)
+{
+ int first = find_delta(base, type);
+ int last = first;
+ int end = nr_deltas - 1;
+
+ if (first < 0) {
+ *first_index = 0;
+ *last_index = -1;
+ return;
+ }
+ while (first > 0 && !memcmp(&deltas[first - 1].base, base, UNION_BASE_SZ))
+ --first;
+ while (last < end && !memcmp(&deltas[last + 1].base, base, UNION_BASE_SZ))
+ ++last;
+ *first_index = first;
+ *last_index = last;
+}
+
+static void sha1_object(const void *data, unsigned long size,
+ enum object_type type, unsigned char *sha1)
+{
+ hash_sha1_file(data, size, typename(type), sha1);
+ if (has_sha1_file(sha1)) {
+ void *has_data;
+ enum object_type has_type;
+ unsigned long has_size;
+ has_data = read_sha1_file(sha1, &has_type, &has_size);
+ if (!has_data)
+ die("cannot read existing object %s", sha1_to_hex(sha1));
+ if (size != has_size || type != has_type ||
+ memcmp(data, has_data, size) != 0)
+ die("SHA1 COLLISION FOUND WITH %s !", sha1_to_hex(sha1));
+ free(has_data);
+ }
+ if (strict) {
+ if (type == OBJ_BLOB) {
+ struct blob *blob = lookup_blob(sha1);
+ if (blob)
+ blob->object.flags |= FLAG_CHECKED;
+ else
+ die("invalid blob object %s", sha1_to_hex(sha1));
+ } else {
+ struct object *obj;
+ int eaten;
+ void *buf = (void *) data;
+
+ /*
+ * we do not need to free the memory here, as the
+ * buf is deleted by the caller.
+ */
+ obj = parse_object_buffer(sha1, type, size, buf, &eaten);
+ if (!obj)
+ die("invalid %s", typename(type));
+ if (fsck_object(obj, 1, fsck_error_function))
+ die("Error in object");
+ if (fsck_walk(obj, mark_link, NULL))
+ die("Not all child objects of %s are reachable", sha1_to_hex(obj->sha1));
+
+ if (obj->type == OBJ_TREE) {
+ struct tree *item = (struct tree *) obj;
+ item->buffer = NULL;
+ }
+ if (obj->type == OBJ_COMMIT) {
+ struct commit *commit = (struct commit *) obj;
+ commit->buffer = NULL;
+ }
+ obj->flags |= FLAG_CHECKED;
+ }
+ }
+}
+
+static int is_delta_type(enum object_type type)
+{
+ return (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA);
+}
+
+/*
+ * This function is part of find_unresolved_deltas(). There are two
+ * walkers going in the opposite ways.
+ *
+ * The first one in find_unresolved_deltas() traverses down from
+ * parent node to children, deflating nodes along the way. However,
+ * memory for deflated nodes is limited by delta_base_cache_limit, so
+ * at some point parent node's deflated content may be freed.
+ *
+ * The second walker is this function, which goes from current node up
+ * to top parent if necessary to deflate the node. In normal
+ * situation, its parent node would be already deflated, so it just
+ * needs to apply delta.
+ *
+ * In the worst case scenario, parent node is no longer deflated because
+ * we're running out of delta_base_cache_limit; we need to re-deflate
+ * parents, possibly up to the top base.
+ *
+ * All deflated objects here are subject to be freed if we exceed
+ * delta_base_cache_limit, just like in find_unresolved_deltas(), we
+ * just need to make sure the last node is not freed.
+ */
+static void *get_base_data(struct base_data *c)
+{
+ if (!c->data) {
+ struct object_entry *obj = c->obj;
+ struct base_data **delta = NULL;
+ int delta_nr = 0, delta_alloc = 0;
+
+ while (is_delta_type(c->obj->type) && !c->data) {
+ ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
+ delta[delta_nr++] = c;
+ c = c->base;
+ }
+ if (!delta_nr) {
+ c->data = get_data_from_pack(obj);
+ c->size = obj->size;
+ base_cache_used += c->size;
+ prune_base_data(c);
+ }
+ for (; delta_nr > 0; delta_nr--) {
+ void *base, *raw;
+ c = delta[delta_nr - 1];
+ obj = c->obj;
+ base = get_base_data(c->base);
+ raw = get_data_from_pack(obj);
+ c->data = patch_delta(
+ base, c->base->size,
+ raw, obj->size,
+ &c->size);
+ free(raw);
+ if (!c->data)
+ bad_object(obj->idx.offset, "failed to apply delta");
+ base_cache_used += c->size;
+ prune_base_data(c);
+ }
+ free(delta);
+ }
+ return c->data;
+}
+
+static void resolve_delta(struct object_entry *delta_obj,
+ struct base_data *base, struct base_data *result)
+{
+ void *base_data, *delta_data;
+
+ delta_obj->real_type = base->obj->real_type;
+ delta_obj->delta_depth = base->obj->delta_depth + 1;
+ if (deepest_delta < delta_obj->delta_depth)
+ deepest_delta = delta_obj->delta_depth;
+ delta_obj->base_object_no = base->obj - objects;
+ delta_data = get_data_from_pack(delta_obj);
+ base_data = get_base_data(base);
+ result->obj = delta_obj;
+ result->data = patch_delta(base_data, base->size,
+ delta_data, delta_obj->size, &result->size);
+ free(delta_data);
+ if (!result->data)
+ bad_object(delta_obj->idx.offset, "failed to apply delta");
+ sha1_object(result->data, result->size, delta_obj->real_type,
+ delta_obj->idx.sha1);
+ nr_resolved_deltas++;
+}
+
+static struct base_data *find_unresolved_deltas_1(struct base_data *base,
+ struct base_data *prev_base)
+{
+ if (base->ref_last == -1 && base->ofs_last == -1) {
+ union delta_base base_spec;
+
+ hashcpy(base_spec.sha1, base->obj->idx.sha1);
+ find_delta_children(&base_spec,
+ &base->ref_first, &base->ref_last, OBJ_REF_DELTA);
+
+ memset(&base_spec, 0, sizeof(base_spec));
+ base_spec.offset = base->obj->idx.offset;
+ find_delta_children(&base_spec,
+ &base->ofs_first, &base->ofs_last, OBJ_OFS_DELTA);
+
+ if (base->ref_last == -1 && base->ofs_last == -1) {
+ free(base->data);
+ return NULL;
+ }
+
+ link_base_data(prev_base, base);
+ }
+
+ if (base->ref_first <= base->ref_last) {
+ struct object_entry *child = objects + deltas[base->ref_first].obj_no;
+ struct base_data *result = alloc_base_data();
+
+ assert(child->real_type == OBJ_REF_DELTA);
+ resolve_delta(child, base, result);
+ if (base->ref_first == base->ref_last && base->ofs_last == -1)
+ free_base_data(base);
+
+ base->ref_first++;
+ return result;
+ }
+
+ if (base->ofs_first <= base->ofs_last) {
+ struct object_entry *child = objects + deltas[base->ofs_first].obj_no;
+ struct base_data *result = alloc_base_data();
+
+ assert(child->real_type == OBJ_OFS_DELTA);
+ resolve_delta(child, base, result);
+ if (base->ofs_first == base->ofs_last)
+ free_base_data(base);
+
+ base->ofs_first++;
+ return result;
+ }
+
+ unlink_base_data(base);
+ return NULL;
+}
+
+static void find_unresolved_deltas(struct base_data *base)
+{
+ struct base_data *new_base, *prev_base = NULL;
+ for (;;) {
+ new_base = find_unresolved_deltas_1(base, prev_base);
+
+ if (new_base) {
+ prev_base = base;
+ base = new_base;
+ } else {
+ free(base);
+ base = prev_base;
+ if (!base)
+ return;
+ prev_base = base->base;
+ }
+ }
+}
+
+static int compare_delta_entry(const void *a, const void *b)
+{
+ const struct delta_entry *delta_a = a;
+ const struct delta_entry *delta_b = b;
+
+ /* group by type (ref vs ofs) and then by value (sha-1 or offset) */
+ return compare_delta_bases(&delta_a->base, &delta_b->base,
+ objects[delta_a->obj_no].type,
+ objects[delta_b->obj_no].type);
+}
+
+/* Parse all objects and return the pack content SHA1 hash */
+static void parse_pack_objects(unsigned char *sha1)
+{
+ int i;
+ struct delta_entry *delta = deltas;
+ struct stat st;
+
+ /*
+ * First pass:
+ * - find locations of all objects;
+ * - calculate SHA1 of all non-delta objects;
+ * - remember base (SHA1 or offset) for all deltas.
+ */
+ if (verbose)
+ progress = start_progress(
+ from_stdin ? "Receiving objects" : "Indexing objects",
+ nr_objects);
+ for (i = 0; i < nr_objects; i++) {
+ struct object_entry *obj = &objects[i];
+ void *data = unpack_raw_entry(obj, &delta->base);
+ obj->real_type = obj->type;
+ if (is_delta_type(obj->type)) {
+ nr_deltas++;
+ delta->obj_no = i;
+ delta++;
+ } else
+ sha1_object(data, obj->size, obj->type, obj->idx.sha1);
+ free(data);
+ display_progress(progress, i+1);
+ }
+ objects[i].idx.offset = consumed_bytes;
+ stop_progress(&progress);
+
+ /* Check pack integrity */
+ flush();
+ git_SHA1_Final(sha1, &input_ctx);
+ if (hashcmp(fill(20), sha1))
+ die("pack is corrupted (SHA1 mismatch)");
+ use(20);
+
+ /* If input_fd is a file, we should have reached its end now. */
+ if (fstat(input_fd, &st))
+ die_errno("cannot fstat packfile");
+ if (S_ISREG(st.st_mode) &&
+ lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
+ die("pack has junk at the end");
+
+ if (!nr_deltas)
+ return;
+
+ /* Sort deltas by base SHA1/offset for fast searching */
+ qsort(deltas, nr_deltas, sizeof(struct delta_entry),
+ compare_delta_entry);
+
+ /*
+ * Second pass:
+ * - for all non-delta objects, look if it is used as a base for
+ * deltas;
+ * - if used as a base, uncompress the object and apply all deltas,
+ * recursively checking if the resulting object is used as a base
+ * for some more deltas.
+ */
+ if (verbose)
+ progress = start_progress("Resolving deltas", nr_deltas);
+ for (i = 0; i < nr_objects; i++) {
+ struct object_entry *obj = &objects[i];
+ struct base_data *base_obj = alloc_base_data();
+
+ if (is_delta_type(obj->type))
+ continue;
+ base_obj->obj = obj;
+ base_obj->data = NULL;
+ find_unresolved_deltas(base_obj);
+ display_progress(progress, nr_resolved_deltas);
+ }
+}
+
+static int write_compressed(struct sha1file *f, void *in, unsigned int size)
+{
+ git_zstream stream;
+ int status;
+ unsigned char outbuf[4096];
+
+ memset(&stream, 0, sizeof(stream));
+ git_deflate_init(&stream, zlib_compression_level);
+ stream.next_in = in;
+ stream.avail_in = size;
+
+ do {
+ stream.next_out = outbuf;
+ stream.avail_out = sizeof(outbuf);
+ status = git_deflate(&stream, Z_FINISH);
+ sha1write(f, outbuf, sizeof(outbuf) - stream.avail_out);
+ } while (status == Z_OK);
+
+ if (status != Z_STREAM_END)
+ die("unable to deflate appended object (%d)", status);
+ size = stream.total_out;
+ git_deflate_end(&stream);
+ return size;
+}
+
+static struct object_entry *append_obj_to_pack(struct sha1file *f,
+ const unsigned char *sha1, void *buf,
+ unsigned long size, enum object_type type)
+{
+ struct object_entry *obj = &objects[nr_objects++];
+ unsigned char header[10];
+ unsigned long s = size;
+ int n = 0;
+ unsigned char c = (type << 4) | (s & 15);
+ s >>= 4;
+ while (s) {
+ header[n++] = c | 0x80;
+ c = s & 0x7f;
+ s >>= 7;
+ }
+ header[n++] = c;
+ crc32_begin(f);
+ sha1write(f, header, n);
+ obj[0].size = size;
+ obj[0].hdr_size = n;
+ obj[0].type = type;
+ obj[0].real_type = type;
+ obj[1].idx.offset = obj[0].idx.offset + n;
+ obj[1].idx.offset += write_compressed(f, buf, size);
+ obj[0].idx.crc32 = crc32_end(f);
+ sha1flush(f);
+ hashcpy(obj->idx.sha1, sha1);
+ return obj;
+}
+
+static int delta_pos_compare(const void *_a, const void *_b)
+{
+ struct delta_entry *a = *(struct delta_entry **)_a;
+ struct delta_entry *b = *(struct delta_entry **)_b;
+ return a->obj_no - b->obj_no;
+}
+
+static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved)
+{
+ struct delta_entry **sorted_by_pos;
+ int i, n = 0;
+
+ /*
+ * Since many unresolved deltas may well be themselves base objects
+ * for more unresolved deltas, we really want to include the
+ * smallest number of base objects that would cover as much delta
+ * as possible by picking the
+ * trunc deltas first, allowing for other deltas to resolve without
+ * additional base objects. Since most base objects are to be found
+ * before deltas depending on them, a good heuristic is to start
+ * resolving deltas in the same order as their position in the pack.
+ */
+ sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos));
+ for (i = 0; i < nr_deltas; i++) {
+ if (objects[deltas[i].obj_no].real_type != OBJ_REF_DELTA)
+ continue;
+ sorted_by_pos[n++] = &deltas[i];
+ }
+ qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare);
+
+ for (i = 0; i < n; i++) {
+ struct delta_entry *d = sorted_by_pos[i];
+ enum object_type type;
+ struct base_data *base_obj = alloc_base_data();
+
+ if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
+ continue;
+ base_obj->data = read_sha1_file(d->base.sha1, &type, &base_obj->size);
+ if (!base_obj->data)
+ continue;
+
+ if (check_sha1_signature(d->base.sha1, base_obj->data,
+ base_obj->size, typename(type)))
+ die("local object %s is corrupt", sha1_to_hex(d->base.sha1));
+ base_obj->obj = append_obj_to_pack(f, d->base.sha1,
+ base_obj->data, base_obj->size, type);
+ find_unresolved_deltas(base_obj);
+ display_progress(progress, nr_resolved_deltas);
+ }
+ free(sorted_by_pos);
+}
+
+static void final(const char *final_pack_name, const char *curr_pack_name,
+ const char *final_index_name, const char *curr_index_name,
+ const char *keep_name, const char *keep_msg,
+ unsigned char *sha1)
+{
+ const char *report = "pack";
+ char name[PATH_MAX];
+ int err;
+
+ if (!from_stdin) {
+ close(input_fd);
+ } else {
+ fsync_or_die(output_fd, curr_pack_name);
+ err = close(output_fd);
+ if (err)
+ die_errno("error while closing pack file");
+ }
+
+ if (keep_msg) {
+ int keep_fd, keep_msg_len = strlen(keep_msg);
+
+ if (!keep_name)
+ keep_fd = odb_pack_keep(name, sizeof(name), sha1);
+ else
+ keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);
+
+ if (keep_fd < 0) {
+ if (errno != EEXIST)
+ die_errno("cannot write keep file '%s'",
+ keep_name);
+ } else {
+ if (keep_msg_len > 0) {
+ write_or_die(keep_fd, keep_msg, keep_msg_len);
+ write_or_die(keep_fd, "\n", 1);
+ }
+ if (close(keep_fd) != 0)
+ die_errno("cannot close written keep file '%s'",
+ keep_name);
+ report = "keep";
+ }
+ }
+
+ if (final_pack_name != curr_pack_name) {
+ if (!final_pack_name) {
+ snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
+ get_object_directory(), sha1_to_hex(sha1));
+ final_pack_name = name;
+ }
+ if (move_temp_to_file(curr_pack_name, final_pack_name))
+ die("cannot store pack file");
+ } else if (from_stdin)
+ chmod(final_pack_name, 0444);
+
+ if (final_index_name != curr_index_name) {
+ if (!final_index_name) {
+ snprintf(name, sizeof(name), "%s/pack/pack-%s.idx",
+ get_object_directory(), sha1_to_hex(sha1));
+ final_index_name = name;
+ }
+ if (move_temp_to_file(curr_index_name, final_index_name))
+ die("cannot store index file");
+ } else
+ chmod(final_index_name, 0444);
+
+ if (!from_stdin) {
+ printf("%s\n", sha1_to_hex(sha1));
+ } else {
+ char buf[48];
+ int len = snprintf(buf, sizeof(buf), "%s\t%s\n",
+ report, sha1_to_hex(sha1));
+ write_or_die(1, buf, len);
+
+ /*
+ * Let's just mimic git-unpack-objects here and write
+ * the last part of the input buffer to stdout.
+ */
+ while (input_len) {
+ err = xwrite(1, input_buffer + input_offset, input_len);
+ if (err <= 0)
+ break;
+ input_len -= err;
+ input_offset += err;
+ }
+ }
+}
+
+static int git_index_pack_config(const char *k, const char *v, void *cb)
+{
+ struct pack_idx_option *opts = cb;
+
+ if (!strcmp(k, "pack.indexversion")) {
+ opts->version = git_config_int(k, v);
+ if (opts->version > 2)
+ die("bad pack.indexversion=%"PRIu32, opts->version);
+ return 0;
+ }
+ return git_default_config(k, v, cb);
+}
+
+static int cmp_uint32(const void *a_, const void *b_)
+{
+ uint32_t a = *((uint32_t *)a_);
+ uint32_t b = *((uint32_t *)b_);
+
+ return (a < b) ? -1 : (a != b);
+}
+
+static void read_v2_anomalous_offsets(struct packed_git *p,
+ struct pack_idx_option *opts)
+{
+ const uint32_t *idx1, *idx2;
+ uint32_t i;
+
+ /* The address of the 4-byte offset table */
+ idx1 = (((const uint32_t *)p->index_data)
+ + 2 /* 8-byte header */
+ + 256 /* fan out */
+ + 5 * p->num_objects /* 20-byte SHA-1 table */
+ + p->num_objects /* CRC32 table */
+ );
+
+ /* The address of the 8-byte offset table */
+ idx2 = idx1 + p->num_objects;
+
+ for (i = 0; i < p->num_objects; i++) {
+ uint32_t off = ntohl(idx1[i]);
+ if (!(off & 0x80000000))
+ continue;
+ off = off & 0x7fffffff;
+ if (idx2[off * 2])
+ continue;
+ /*
+ * The real offset is ntohl(idx2[off * 2]) in high 4
+ * octets, and ntohl(idx2[off * 2 + 1]) in low 4
+ * octets. But idx2[off * 2] is Zero!!!
+ */
+ ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
+ opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
+ }
+
+ if (1 < opts->anomaly_nr)
+ qsort(opts->anomaly, opts->anomaly_nr, sizeof(uint32_t), cmp_uint32);
+}
+
+static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
+{
+ struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
+
+ if (!p)
+ die("Cannot open existing pack file '%s'", pack_name);
+ if (open_pack_index(p))
+ die("Cannot open existing pack idx file for '%s'", pack_name);
+
+ /* Read the attributes from the existing idx file */
+ opts->version = p->index_version;
+
+ if (opts->version == 2)
+ read_v2_anomalous_offsets(p, opts);
+
+ /*
+ * Get rid of the idx file as we do not need it anymore.
+ * NEEDSWORK: extract this bit from free_pack_by_name() in
+ * sha1_file.c, perhaps? It shouldn't matter very much as we
+ * know we haven't installed this pack (hence we never have
+ * read anything from it).
+ */
+ close_pack_index(p);
+ free(p);
+}
+
+static void show_pack_info(int stat_only)
+{
+ int i, baseobjects = nr_objects - nr_deltas;
+ unsigned long *chain_histogram = NULL;
+
+ if (deepest_delta)
+ chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
+
+ for (i = 0; i < nr_objects; i++) {
+ struct object_entry *obj = &objects[i];
+
+ if (is_delta_type(obj->type))
+ chain_histogram[obj->delta_depth - 1]++;
+ if (stat_only)
+ continue;
+ printf("%s %-6s %lu %lu %"PRIuMAX,
+ sha1_to_hex(obj->idx.sha1),
+ typename(obj->real_type), obj->size,
+ (unsigned long)(obj[1].idx.offset - obj->idx.offset),
+ (uintmax_t)obj->idx.offset);
+ if (is_delta_type(obj->type)) {
+ struct object_entry *bobj = &objects[obj->base_object_no];
+ printf(" %u %s", obj->delta_depth, sha1_to_hex(bobj->idx.sha1));
+ }
+ putchar('\n');
+ }
+
+ if (baseobjects)
+ printf("non delta: %d object%s\n",
+ baseobjects, baseobjects > 1 ? "s" : "");
+ for (i = 0; i < deepest_delta; i++) {
+ if (!chain_histogram[i])
+ continue;
+ printf("chain length = %d: %lu object%s\n",
+ i + 1,
+ chain_histogram[i],
+ chain_histogram[i] > 1 ? "s" : "");
+ }
+}
+
+int cmd_index_pack(int argc, const char **argv, const char *prefix)
+{
+ int i, fix_thin_pack = 0, verify = 0, stat_only = 0, stat = 0;
+ const char *curr_pack, *curr_index;
+ const char *index_name = NULL, *pack_name = NULL;
+ const char *keep_name = NULL, *keep_msg = NULL;
+ char *index_name_buf = NULL, *keep_name_buf = NULL;
+ struct pack_idx_entry **idx_objects;
+ struct pack_idx_option opts;
+ unsigned char pack_sha1[20];
+
+ if (argc == 2 && !strcmp(argv[1], "-h"))
+ usage(index_pack_usage);
+
+ read_replace_refs = 0;
+
+ reset_pack_idx_option(&opts);
+ git_config(git_index_pack_config, &opts);
+ if (prefix && chdir(prefix))
+ die("Cannot come back to cwd");
+
+ for (i = 1; i < argc; i++) {
+ const char *arg = argv[i];
+
+ if (*arg == '-') {
+ if (!strcmp(arg, "--stdin")) {
+ from_stdin = 1;
+ } else if (!strcmp(arg, "--fix-thin")) {
+ fix_thin_pack = 1;
+ } else if (!strcmp(arg, "--strict")) {
+ strict = 1;
+ } else if (!strcmp(arg, "--verify")) {
+ verify = 1;
+ } else if (!strcmp(arg, "--verify-stat")) {
+ verify = 1;
+ stat = 1;
+ } else if (!strcmp(arg, "--verify-stat-only")) {
+ verify = 1;
+ stat = 1;
+ stat_only = 1;
+ } else if (!strcmp(arg, "--keep")) {
+ keep_msg = "";
+ } else if (!prefixcmp(arg, "--keep=")) {
+ keep_msg = arg + 7;
+ } else if (!prefixcmp(arg, "--pack_header=")) {
+ struct pack_header *hdr;
+ char *c;
+
+ hdr = (struct pack_header *)input_buffer;
+ hdr->hdr_signature = htonl(PACK_SIGNATURE);
+ hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
+ if (*c != ',')
+ die("bad %s", arg);
+ hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
+ if (*c)
+ die("bad %s", arg);
+ input_len = sizeof(*hdr);
+ } else if (!strcmp(arg, "-v")) {
+ verbose = 1;
+ } else if (!strcmp(arg, "-o")) {
+ if (index_name || (i+1) >= argc)
+ usage(index_pack_usage);
+ index_name = argv[++i];
+ } else if (!prefixcmp(arg, "--index-version=")) {
+ char *c;
+ opts.version = strtoul(arg + 16, &c, 10);
+ if (opts.version > 2)
+ die("bad %s", arg);
+ if (*c == ',')
+ opts.off32_limit = strtoul(c+1, &c, 0);
+ if (*c || opts.off32_limit & 0x80000000)
+ die("bad %s", arg);
+ } else
+ usage(index_pack_usage);
+ continue;
+ }
+
+ if (pack_name)
+ usage(index_pack_usage);
+ pack_name = arg;
+ }
+
+ if (!pack_name && !from_stdin)
+ usage(index_pack_usage);
+ if (fix_thin_pack && !from_stdin)
+ die("--fix-thin cannot be used without --stdin");
+ if (!index_name && pack_name) {
+ int len = strlen(pack_name);
+ if (!has_extension(pack_name, ".pack"))
+ die("packfile name '%s' does not end with '.pack'",
+ pack_name);
+ index_name_buf = xmalloc(len);
+ memcpy(index_name_buf, pack_name, len - 5);
+ strcpy(index_name_buf + len - 5, ".idx");
+ index_name = index_name_buf;
+ }
+ if (keep_msg && !keep_name && pack_name) {
+ int len = strlen(pack_name);
+ if (!has_extension(pack_name, ".pack"))
+ die("packfile name '%s' does not end with '.pack'",
+ pack_name);
+ keep_name_buf = xmalloc(len);
+ memcpy(keep_name_buf, pack_name, len - 5);
+ strcpy(keep_name_buf + len - 5, ".keep");
+ keep_name = keep_name_buf;
+ }
+ if (verify) {
+ if (!index_name)
+ die("--verify with no packfile name given");
+ read_idx_option(&opts, index_name);
+ opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
+ }
+ if (strict)
+ opts.flags |= WRITE_IDX_STRICT;
+
+ curr_pack = open_pack_file(pack_name);
+ parse_pack_header();
+ objects = xcalloc(nr_objects + 1, sizeof(struct object_entry));
+ deltas = xcalloc(nr_objects, sizeof(struct delta_entry));
+ parse_pack_objects(pack_sha1);
+ if (nr_deltas == nr_resolved_deltas) {
+ stop_progress(&progress);
+ /* Flush remaining pack final 20-byte SHA1. */
+ flush();
+ } else {
+ if (fix_thin_pack) {
+ struct sha1file *f;
+ unsigned char read_sha1[20], tail_sha1[20];
+ char msg[48];
+ int nr_unresolved = nr_deltas - nr_resolved_deltas;
+ int nr_objects_initial = nr_objects;
+ if (nr_unresolved <= 0)
+ die("confusion beyond insanity");
+ objects = xrealloc(objects,
+ (nr_objects + nr_unresolved + 1)
+ * sizeof(*objects));
+ f = sha1fd(output_fd, curr_pack);
+ fix_unresolved_deltas(f, nr_unresolved);
+ sprintf(msg, "completed with %d local objects",
+ nr_objects - nr_objects_initial);
+ stop_progress_msg(&progress, msg);
+ sha1close(f, tail_sha1, 0);
+ hashcpy(read_sha1, pack_sha1);
+ fixup_pack_header_footer(output_fd, pack_sha1,
+ curr_pack, nr_objects,
+ read_sha1, consumed_bytes-20);
+ if (hashcmp(read_sha1, tail_sha1) != 0)
+ die("Unexpected tail checksum for %s "
+ "(disk corruption?)", curr_pack);
+ }
+ if (nr_deltas != nr_resolved_deltas)
+ die("pack has %d unresolved deltas",
+ nr_deltas - nr_resolved_deltas);
+ }
+ free(deltas);
+ if (strict)
+ check_objects();
+
+ if (stat)
+ show_pack_info(stat_only);
+
+ idx_objects = xmalloc((nr_objects) * sizeof(struct pack_idx_entry *));
+ for (i = 0; i < nr_objects; i++)
+ idx_objects[i] = &objects[i].idx;
+ curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_sha1);
+ free(idx_objects);
+
+ if (!verify)
+ final(pack_name, curr_pack,
+ index_name, curr_index,
+ keep_name, keep_msg,
+ pack_sha1);
+ else
+ close(input_fd);
+ free(objects);
+ free(index_name_buf);
+ free(keep_name_buf);
+ if (pack_name == NULL)
+ free((void *) curr_pack);
+ if (index_name == NULL)
+ free((void *) curr_index);
+
+ return 0;
+}