]> git.ipfire.org Git - thirdparty/git.git/blobdiff - sha1_file.c
glossary: define commit-ish (a.k.a. committish)
[thirdparty/git.git] / sha1_file.c
index b114cc922d4abce741b56e9da11fbef1382b4008..8e27db1bd2b49f28b235fcd7e18a0dda43a1f045 100644 (file)
@@ -36,6 +36,9 @@ static inline uintmax_t sz_fmt(size_t s) { return s; }
 
 const unsigned char null_sha1[20];
 
+static const char *no_log_pack_access = "no_log_pack_access";
+static const char *log_pack_access;
+
 /*
  * This is meant to hold a *small* number of objects that you would
  * want read_sha1_file() to be able to return, but yet you do not want
@@ -1303,6 +1306,26 @@ static int git_open_noatime(const char *name)
        }
 }
 
+static int stat_sha1_file(const unsigned char *sha1, struct stat *st)
+{
+       char *name = sha1_file_name(sha1);
+       struct alternate_object_database *alt;
+
+       if (!lstat(name, st))
+               return 0;
+
+       prepare_alt_odb();
+       errno = ENOENT;
+       for (alt = alt_odb_list; alt; alt = alt->next) {
+               name = alt->name;
+               fill_sha1_path(name, sha1);
+               if (!lstat(alt->base, st))
+                       return 0;
+       }
+
+       return -1;
+}
+
 static int open_sha1_file(const unsigned char *sha1)
 {
        int fd;
@@ -1690,46 +1713,21 @@ static int retry_bad_packed_offset(struct packed_git *p, off_t obj_offset)
        return type;
 }
 
-
 #define POI_STACK_PREALLOC 64
 
-static int packed_object_info(struct packed_git *p, off_t obj_offset,
-                             unsigned long *sizep, int *rtype)
+static enum object_type packed_to_object_type(struct packed_git *p,
+                                             off_t obj_offset,
+                                             enum object_type type,
+                                             struct pack_window **w_curs,
+                                             off_t curpos)
 {
-       struct pack_window *w_curs = NULL;
-       unsigned long size;
-       off_t curpos = obj_offset;
-       enum object_type type;
        off_t small_poi_stack[POI_STACK_PREALLOC];
        off_t *poi_stack = small_poi_stack;
        int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
 
-       type = unpack_object_header(p, &w_curs, &curpos, &size);
-
-       if (rtype)
-               *rtype = type; /* representation type */
-
-       if (sizep) {
-               if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
-                       off_t tmp_pos = curpos;
-                       off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
-                                                          type, obj_offset);
-                       if (!base_offset) {
-                               type = OBJ_BAD;
-                               goto out;
-                       }
-                       *sizep = get_size_from_delta(p, &w_curs, tmp_pos);
-                       if (*sizep == 0) {
-                               type = OBJ_BAD;
-                               goto out;
-                       }
-               } else {
-                       *sizep = size;
-               }
-       }
-
        while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
                off_t base_offset;
+               unsigned long size;
                /* Push the object we're going to leave behind */
                if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
                        poi_stack_alloc = alloc_nr(poi_stack_nr);
@@ -1740,11 +1738,11 @@ static int packed_object_info(struct packed_git *p, off_t obj_offset,
                }
                poi_stack[poi_stack_nr++] = obj_offset;
                /* If parsing the base offset fails, just unwind */
-               base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
+               base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
                if (!base_offset)
                        goto unwind;
                curpos = obj_offset = base_offset;
-               type = unpack_object_header(p, &w_curs, &curpos, &size);
+               type = unpack_object_header(p, w_curs, &curpos, &size);
                if (type <= OBJ_NONE) {
                        /* If getting the base itself fails, we first
                         * retry the base, otherwise unwind */
@@ -1771,7 +1769,6 @@ static int packed_object_info(struct packed_git *p, off_t obj_offset,
 out:
        if (poi_stack != small_poi_stack)
                free(poi_stack);
-       unuse_pack(&w_curs);
        return type;
 
 unwind:
@@ -1785,6 +1782,57 @@ unwind:
        goto out;
 }
 
+static int packed_object_info(struct packed_git *p, off_t obj_offset,
+                             struct object_info *oi)
+{
+       struct pack_window *w_curs = NULL;
+       unsigned long size;
+       off_t curpos = obj_offset;
+       enum object_type type;
+
+       /*
+        * We always get the representation type, but only convert it to
+        * a "real" type later if the caller is interested.
+        */
+       type = unpack_object_header(p, &w_curs, &curpos, &size);
+
+       if (oi->sizep) {
+               if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
+                       off_t tmp_pos = curpos;
+                       off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
+                                                          type, obj_offset);
+                       if (!base_offset) {
+                               type = OBJ_BAD;
+                               goto out;
+                       }
+                       *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
+                       if (*oi->sizep == 0) {
+                               type = OBJ_BAD;
+                               goto out;
+                       }
+               } else {
+                       *oi->sizep = size;
+               }
+       }
+
+       if (oi->disk_sizep) {
+               struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
+               *oi->disk_sizep = revidx[1].offset - obj_offset;
+       }
+
+       if (oi->typep) {
+               *oi->typep = packed_to_object_type(p, obj_offset, type, &w_curs, curpos);
+               if (*oi->typep < 0) {
+                       type = OBJ_BAD;
+                       goto out;
+               }
+       }
+
+out:
+       unuse_pack(&w_curs);
+       return type;
+}
+
 static void *unpack_compressed_entry(struct packed_git *p,
                                    struct pack_window **w_curs,
                                    off_t curpos,
@@ -1956,12 +2004,19 @@ static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
 {
        static FILE *log_file;
 
+       if (!log_pack_access)
+               log_pack_access = getenv("GIT_TRACE_PACK_ACCESS");
+       if (!log_pack_access)
+               log_pack_access = no_log_pack_access;
+       if (log_pack_access == no_log_pack_access)
+               return;
+
        if (!log_file) {
                log_file = fopen(log_pack_access, "w");
                if (!log_file) {
                        error("cannot open pack access log '%s' for writing: %s",
                              log_pack_access, strerror(errno));
-                       log_pack_access = NULL;
+                       log_pack_access = no_log_pack_access;
                        return;
                }
        }
@@ -1992,7 +2047,7 @@ void *unpack_entry(struct packed_git *p, off_t obj_offset,
        int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
        int base_from_cache = 0;
 
-       if (log_pack_access)
+       if (log_pack_access != no_log_pack_access)
                write_pack_access_log(p, obj_offset);
 
        /* PHASE 1: drill down to the innermost base object */
@@ -2135,8 +2190,17 @@ void *unpack_entry(struct packed_git *p, off_t obj_offset,
                data = patch_delta(base, base_size,
                                   delta_data, delta_size,
                                   &size);
+
+               /*
+                * We could not apply the delta; warn the user, but keep going.
+                * Our failure will be noticed either in the next iteration of
+                * the loop, or if this is the final delta, in the caller when
+                * we return NULL. Those code paths will take care of making
+                * a more explicit warning and retrying with another copy of
+                * the object.
+                */
                if (!data)
-                       die("failed to apply delta");
+                       error("failed to apply delta");
 
                free(delta_data);
        }
@@ -2338,7 +2402,8 @@ struct packed_git *find_sha1_pack(const unsigned char *sha1,
 
 }
 
-static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *sizep)
+static int sha1_loose_object_info(const unsigned char *sha1,
+                                 struct object_info *oi)
 {
        int status;
        unsigned long mapsize, size;
@@ -2346,19 +2411,37 @@ static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *size
        git_zstream stream;
        char hdr[32];
 
+       /*
+        * If we don't care about type or size, then we don't
+        * need to look inside the object at all.
+        */
+       if (!oi->typep && !oi->sizep) {
+               if (oi->disk_sizep) {
+                       struct stat st;
+                       if (stat_sha1_file(sha1, &st) < 0)
+                               return -1;
+                       *oi->disk_sizep = st.st_size;
+               }
+               return 0;
+       }
+
        map = map_sha1_file(sha1, &mapsize);
        if (!map)
-               return error("unable to find %s", sha1_to_hex(sha1));
+               return -1;
+       if (oi->disk_sizep)
+               *oi->disk_sizep = mapsize;
        if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
                status = error("unable to unpack %s header",
                               sha1_to_hex(sha1));
        else if ((status = parse_sha1_header(hdr, &size)) < 0)
                status = error("unable to parse %s header", sha1_to_hex(sha1));
-       else if (sizep)
-               *sizep = size;
+       else if (oi->sizep)
+               *oi->sizep = size;
        git_inflate_end(&stream);
        munmap(map, mapsize);
-       return status;
+       if (oi->typep)
+               *oi->typep = status;
+       return 0;
 }
 
 /* returns enum object_type or negative */
@@ -2366,34 +2449,37 @@ int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi)
 {
        struct cached_object *co;
        struct pack_entry e;
-       int status, rtype;
+       int rtype;
 
        co = find_cached_object(sha1);
        if (co) {
+               if (oi->typep)
+                       *(oi->typep) = co->type;
                if (oi->sizep)
                        *(oi->sizep) = co->size;
+               if (oi->disk_sizep)
+                       *(oi->disk_sizep) = 0;
                oi->whence = OI_CACHED;
-               return co->type;
+               return 0;
        }
 
        if (!find_pack_entry(sha1, &e)) {
                /* Most likely it's a loose object. */
-               status = sha1_loose_object_info(sha1, oi->sizep);
-               if (status >= 0) {
+               if (!sha1_loose_object_info(sha1, oi)) {
                        oi->whence = OI_LOOSE;
-                       return status;
+                       return 0;
                }
 
                /* Not a loose object; someone else may have just packed it. */
                reprepare_packed_git();
                if (!find_pack_entry(sha1, &e))
-                       return status;
+                       return -1;
        }
 
-       status = packed_object_info(e.p, e.offset, oi->sizep, &rtype);
-       if (status < 0) {
+       rtype = packed_object_info(e.p, e.offset, oi);
+       if (rtype < 0) {
                mark_bad_packed_object(e.p, sha1);
-               status = sha1_object_info_extended(sha1, oi);
+               return sha1_object_info_extended(sha1, oi);
        } else if (in_delta_base_cache(e.p, e.offset)) {
                oi->whence = OI_DBCACHED;
        } else {
@@ -2404,15 +2490,19 @@ int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi)
                                         rtype == OBJ_OFS_DELTA);
        }
 
-       return status;
+       return 0;
 }
 
 int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
 {
-       struct object_info oi;
+       enum object_type type;
+       struct object_info oi = {NULL};
 
+       oi.typep = &type;
        oi.sizep = sizep;
-       return sha1_object_info_extended(sha1, &oi);
+       if (sha1_object_info_extended(sha1, &oi) < 0)
+               return -1;
+       return type;
 }
 
 static void *read_packed_sha1(const unsigned char *sha1,