Merge in fixes up to 1.0.3 maintenance branch.
[gitweb.git] / pack-objects.c
index e9764604f6f17f4eb018b4fd7247550e90583f8c..caf3b6be5a1cf85bafd034ed9e2cbe3cd596b26c 100644 (file)
@@ -1,30 +1,26 @@
-#include <ctype.h>
 #include "cache.h"
 #include "object.h"
 #include "delta.h"
+#include "pack.h"
 #include "csum-file.h"
 
-static const char pack_usage[] = "git-pack-objects [--window=N] [--depth=N] {--stdout | base-name} < object-list";
+static const char pack_usage[] = "git-pack-objects [--non-empty] [--local] [--incremental] [--window=N] [--depth=N] {--stdout | base-name} < object-list";
 
-/*
- * The object type is a single-character shorthand:
- *  - 'C' for "Commit"
- *  - 'T' for "Tree"
- *  - 'B' for "Blob"
- *  - 'G' for "taG"
- *  - 'D' for "Delta"
- */
 struct object_entry {
        unsigned char sha1[20];
        unsigned long size;
        unsigned long offset;
        unsigned int depth;
        unsigned int hash;
-       unsigned char type;
+       enum object_type type;
        unsigned long delta_size;
        struct object_entry *delta;
 };
 
+static unsigned char object_list_sha1[20];
+static int non_empty = 0;
+static int local = 0;
+static int incremental = 0;
 static struct object_entry **sorted_by_sha, **sorted_by_type;
 static struct object_entry *objects = NULL;
 static int nr_objects = 0, nr_alloc = 0;
@@ -41,7 +37,7 @@ static void *delta_against(void *buf, unsigned long size, struct object_entry *e
        if (!otherbuf)
                die("unable to read %s", sha1_to_hex(entry->delta->sha1));
         delta_buf = diff_delta(otherbuf, othersize,
-                              buf, size, &delta_size, ~0UL);
+                              buf, size, &delta_size, 0);
         if (!delta_buf || delta_size != entry->delta_size)
                die("delta size changed");
         free(buf);
@@ -49,13 +45,41 @@ static void *delta_against(void *buf, unsigned long size, struct object_entry *e
        return delta_buf;
 }
 
+/*
+ * The per-object header is a pretty dense thing, which is
+ *  - first byte: low four bits are "size", then three bits of "type",
+ *    and the high bit is "size continues".
+ *  - each byte afterwards: low seven bits are size continuation,
+ *    with the high bit being "size continues"
+ */
+static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
+{
+       int n = 1;
+       unsigned char c;
+
+       if (type < OBJ_COMMIT || type > OBJ_DELTA)
+               die("bad type %d", type);
+
+       c = (type << 4) | (size & 15);
+       size >>= 4;
+       while (size) {
+               *hdr++ = c | 0x80;
+               c = size & 0x7f;
+               size >>= 7;
+               n++;
+       }
+       *hdr = c;
+       return n;
+}
+
 static unsigned long write_object(struct sha1file *f, struct object_entry *entry)
 {
        unsigned long size;
        char type[10];
        void *buf = read_sha1_file(entry->sha1, type, &size);
-       char header[25];
+       unsigned char header[10];
        unsigned hdrlen, datalen;
+       enum object_type obj_type;
 
        if (!buf)
                die("unable to read %s", sha1_to_hex(entry->sha1));
@@ -63,43 +87,64 @@ static unsigned long write_object(struct sha1file *f, struct object_entry *entry
                die("object %s size inconsistency (%lu vs %lu)", sha1_to_hex(entry->sha1), size, entry->size);
 
        /*
-        * The object header is a byte of 'type' followed by four bytes of
-        * length, except for deltas that has the 20 bytes of delta sha
-        * instead.
+        * The object header is a byte of 'type' followed by zero or
+        * more bytes of length.  For deltas, the 20 bytes of delta sha1
+        * follows that.
         */
-       header[0] = entry->type;
-       hdrlen = 5;
+       obj_type = entry->type;
        if (entry->delta) {
-               header[0] = 'D';
-               memcpy(header+5, entry->delta, 20);
                buf = delta_against(buf, size, entry);
                size = entry->delta_size;
-               hdrlen = 25;
+               obj_type = OBJ_DELTA;
        }
-       datalen = htonl(size);
-       memcpy(header+1, &datalen, 4);
+       hdrlen = encode_header(obj_type, size, header);
        sha1write(f, header, hdrlen);
+       if (entry->delta) {
+               sha1write(f, entry->delta, 20);
+               hdrlen += 20;
+       }
        datalen = sha1write_compressed(f, buf, size);
        free(buf);
        return hdrlen + datalen;
 }
 
+static unsigned long write_one(struct sha1file *f,
+                              struct object_entry *e,
+                              unsigned long offset)
+{
+       if (e->offset)
+               /* offset starts from header size and cannot be zero
+                * if it is written already.
+                */
+               return offset;
+       e->offset = offset;
+       offset += write_object(f, e);
+       /* if we are delitified, write out its base object. */
+       if (e->delta)
+               offset = write_one(f, e->delta, offset);
+       return offset;
+}
+
 static void write_pack_file(void)
 {
        int i;
        struct sha1file *f;
-       unsigned long offset = 0;
+       unsigned long offset;
        unsigned long mb;
+       struct pack_header hdr;
 
        if (!base_name)
                f = sha1fd(1, "<stdout>");
        else
-               f = sha1create("%s.%s", base_name, "pack");
-       for (i = 0; i < nr_objects; i++) {
-               struct object_entry *entry = objects + i;
-               entry->offset = offset;
-               offset += write_object(f, entry);
-       }
+               f = sha1create("%s-%s.%s", base_name, sha1_to_hex(object_list_sha1), "pack");
+       hdr.hdr_signature = htonl(PACK_SIGNATURE);
+       hdr.hdr_version = htonl(PACK_VERSION);
+       hdr.hdr_entries = htonl(nr_objects);
+       sha1write(f, &hdr, sizeof(hdr));
+       offset = sizeof(hdr);
+       for (i = 0; i < nr_objects; i++)
+               offset = write_one(f, objects + i, offset);
+
        sha1close(f, pack_file_sha1, 1);
        mb = offset >> 20;
        offset &= 0xfffff;
@@ -108,7 +153,7 @@ static void write_pack_file(void)
 static void write_index_file(void)
 {
        int i;
-       struct sha1file *f = sha1create("%s.%s", base_name, "idx");
+       struct sha1file *f = sha1create("%s-%s.%s", base_name, sha1_to_hex(object_list_sha1), "idx");
        struct object_entry **list = sorted_by_sha;
        struct object_entry **last = list + nr_objects;
        unsigned int array[256];
@@ -145,11 +190,26 @@ static void write_index_file(void)
        sha1close(f, NULL, 1);
 }
 
-static void add_object_entry(unsigned char *sha1, unsigned int hash)
+static int add_object_entry(unsigned char *sha1, unsigned int hash)
 {
        unsigned int idx = nr_objects;
        struct object_entry *entry;
 
+       if (incremental || local) {
+               struct packed_git *p;
+
+               for (p = packed_git; p; p = p->next) {
+                       struct pack_entry e;
+
+                       if (find_pack_entry_one(sha1, &e, p)) {
+                               if (incremental)
+                                       return 0;
+                               if (local && !p->pack_local)
+                                       return 0;
+                       }
+               }
+       }
+
        if (idx >= nr_alloc) {
                unsigned int needed = (idx + 1024) * 3 / 2;
                objects = xrealloc(objects, needed * sizeof(*entry));
@@ -160,6 +220,7 @@ static void add_object_entry(unsigned char *sha1, unsigned int hash)
        memcpy(entry->sha1, sha1, 20);
        entry->hash = hash;
        nr_objects = idx+1;
+       return 1;
 }
 
 static void check_object(struct object_entry *entry)
@@ -168,13 +229,13 @@ static void check_object(struct object_entry *entry)
 
        if (!sha1_object_info(entry->sha1, type, &entry->size)) {
                if (!strcmp(type, "commit")) {
-                       entry->type = 'C';
+                       entry->type = OBJ_COMMIT;
                } else if (!strcmp(type, "tree")) {
-                       entry->type = 'T';
+                       entry->type = OBJ_TREE;
                } else if (!strcmp(type, "blob")) {
-                       entry->type = 'B';
+                       entry->type = OBJ_BLOB;
                } else if (!strcmp(type, "tag")) {
-                       entry->type = 'G';
+                       entry->type = OBJ_TAG;
                } else
                        die("unable to pack object %s of type %s",
                            sha1_to_hex(entry->sha1), type);
@@ -333,18 +394,103 @@ static void find_deltas(struct object_entry **list, int window, int depth)
                if (idx >= window)
                        idx = 0;
        }
+
+       for (i = 0; i < window; ++i)
+               free(array[i].data);
+       free(array);
+}
+
+static void prepare_pack(int window, int depth)
+{
+       get_object_details();
+
+       fprintf(stderr, "Packing %d objects\n", nr_objects);
+
+       sorted_by_type = create_sorted_list(type_size_sort);
+       if (window && depth)
+               find_deltas(sorted_by_type, window+1, depth);
+       write_pack_file();
+}
+
+static int reuse_cached_pack(unsigned char *sha1, int pack_to_stdout)
+{
+       static const char cache[] = "pack-cache/pack-%s.%s";
+       char *cached_pack, *cached_idx;
+       int ifd, ofd, ifd_ix = -1;
+
+       cached_pack = git_path(cache, sha1_to_hex(sha1), "pack");
+       ifd = open(cached_pack, O_RDONLY);
+       if (ifd < 0)
+               return 0;
+
+       if (!pack_to_stdout) {
+               cached_idx = git_path(cache, sha1_to_hex(sha1), "idx");
+               ifd_ix = open(cached_idx, O_RDONLY);
+               if (ifd_ix < 0) {
+                       close(ifd);
+                       return 0;
+               }
+       }
+
+       fprintf(stderr, "Reusing %d objects pack %s\n", nr_objects,
+               sha1_to_hex(sha1));
+
+       if (pack_to_stdout) {
+               if (copy_fd(ifd, 1))
+                       exit(1);
+               close(ifd);
+       }
+       else {
+               char name[PATH_MAX];
+               snprintf(name, sizeof(name),
+                        "%s-%s.%s", base_name, sha1_to_hex(sha1), "pack");
+               ofd = open(name, O_CREAT | O_EXCL | O_WRONLY, 0666);
+               if (ofd < 0)
+                       die("unable to open %s (%s)", name, strerror(errno));
+               if (copy_fd(ifd, ofd))
+                       exit(1);
+               close(ifd);
+
+               snprintf(name, sizeof(name),
+                        "%s-%s.%s", base_name, sha1_to_hex(sha1), "idx");
+               ofd = open(name, O_CREAT | O_EXCL | O_WRONLY, 0666);
+               if (ofd < 0)
+                       die("unable to open %s (%s)", name, strerror(errno));
+               if (copy_fd(ifd_ix, ofd))
+                       exit(1);
+               close(ifd_ix);
+               puts(sha1_to_hex(sha1));
+       }
+
+       return 1;
 }
 
 int main(int argc, char **argv)
 {
+       SHA_CTX ctx;
        char line[PATH_MAX + 20];
        int window = 10, depth = 10, pack_to_stdout = 0;
+       struct object_entry **list;
        int i;
 
+       setup_git_directory();
+
        for (i = 1; i < argc; i++) {
                const char *arg = argv[i];
 
                if (*arg == '-') {
+                       if (!strcmp("--non-empty", arg)) {
+                               non_empty = 1;
+                               continue;
+                       }
+                       if (!strcmp("--local", arg)) {
+                               local = 1;
+                               continue;
+                       }
+                       if (!strcmp("--incremental", arg)) {
+                               incremental = 1;
+                               continue;
+                       }
                        if (!strncmp("--window=", arg, 9)) {
                                char *end;
                                window = strtoul(arg+9, &end, 0);
@@ -373,13 +519,14 @@ int main(int argc, char **argv)
        if (pack_to_stdout != !base_name)
                usage(pack_usage);
 
+       prepare_packed_git();
        while (fgets(line, sizeof(line), stdin) != NULL) {
                unsigned int hash;
                char *p;
                unsigned char sha1[20];
 
                if (get_sha1_hex(line, sha1))
-                       die("expected sha1, got garbage");
+                       die("expected sha1, got garbage:\n %s", line);
                hash = 0;
                p = line+40;
                while (*p) {
@@ -390,17 +537,26 @@ int main(int argc, char **argv)
                }
                add_object_entry(sha1, hash);
        }
-       get_object_details();
-
-       fprintf(stderr, "Packing %d objects\n", nr_objects);
+       if (non_empty && !nr_objects)
+               return 0;
 
        sorted_by_sha = create_sorted_list(sha1_sort);
-       sorted_by_type = create_sorted_list(type_size_sort);
-       if (window && depth)
-               find_deltas(sorted_by_type, window+1, depth);
-
-       write_pack_file();
-       if (!pack_to_stdout)
-               write_index_file();
+       SHA1_Init(&ctx);
+       list = sorted_by_sha;
+       for (i = 0; i < nr_objects; i++) {
+               struct object_entry *entry = *list++;
+               SHA1_Update(&ctx, entry->sha1, 20);
+       }
+       SHA1_Final(object_list_sha1, &ctx);
+
+       if (reuse_cached_pack(object_list_sha1, pack_to_stdout))
+               ;
+       else {
+               prepare_pack(window, depth);
+               if (!pack_to_stdout) {
+                       write_index_file();
+                       puts(sha1_to_hex(object_list_sha1));
+               }
+       }
        return 0;
 }