Allow git-svnimport to take "" as the trunk directory.
[gitweb.git] / sha1_file.c
index ae9bd1fc2f9eca19b9708fef876faff16fd917fe..aca741b79ce3cdc28f0eb5bdc6848ddba6da8f35 100644 (file)
@@ -13,6 +13,7 @@
 #include "commit.h"
 #include "tag.h"
 #include "tree.h"
+#include "refs.h"
 
 #ifndef O_NOATIME
 #if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
@@ -192,7 +193,7 @@ char *sha1_pack_name(const unsigned char *sha1)
                *buf++ = hex[val >> 4];
                *buf++ = hex[val & 0xf];
        }
-       
+
        return base;
 }
 
@@ -217,7 +218,7 @@ char *sha1_pack_index_name(const unsigned char *sha1)
                *buf++ = hex[val >> 4];
                *buf++ = hex[val & 0xf];
        }
-       
+
        return base;
 }
 
@@ -351,10 +352,14 @@ static void read_info_alternates(const char * relative_base, int depth)
        char *map;
        size_t mapsz;
        struct stat st;
-       char path[PATH_MAX];
+       const char alt_file_name[] = "info/alternates";
+       /* Given that relative_base is no longer than PATH_MAX,
+          ensure that "path" has enough space to append "/", the
+          file name, "info/alternates", and a trailing NUL.  */
+       char path[PATH_MAX + 1 + sizeof alt_file_name];
        int fd;
 
-       sprintf(path, "%s/info/alternates", relative_base);
+       sprintf(path, "%s/%s", relative_base, alt_file_name);
        fd = open(path, O_RDONLY);
        if (fd < 0)
                return;
@@ -375,11 +380,12 @@ void prepare_alt_odb(void)
 {
        const char *alt;
 
+       if (alt_odb_tail)
+               return;
+
        alt = getenv(ALTERNATE_DB_ENVIRONMENT);
        if (!alt) alt = "";
 
-       if (alt_odb_tail)
-               return;
        alt_odb_tail = &alt_odb_list;
        link_alt_odb_entries(alt, alt + strlen(alt), ':', NULL, 0);
 
@@ -411,7 +417,7 @@ static size_t peak_pack_mapped;
 static size_t pack_mapped;
 struct packed_git *packed_git;
 
-void pack_report()
+void pack_report(void)
 {
        fprintf(stderr,
                "pack_report: getpagesize()            = %10" SZ_FMT "\n"
@@ -437,7 +443,7 @@ static int check_packed_git_idx(const char *path,  struct packed_git *p)
        void *idx_map;
        struct pack_idx_header *hdr;
        size_t idx_size;
-       uint32_t nr, i, *index;
+       uint32_t version, nr, i, *index;
        int fd = open(path, O_RDONLY);
        struct stat st;
 
@@ -455,21 +461,23 @@ static int check_packed_git_idx(const char *path,  struct packed_git *p)
        idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
        close(fd);
 
-       /* a future index format would start with this, as older git
-        * binaries would fail the non-monotonic index check below.
-        * give a nicer warning to the user if we can.
-        */
        hdr = idx_map;
        if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
-               munmap(idx_map, idx_size);
-               return error("index file %s is a newer version"
-                       " and is not supported by this binary"
-                       " (try upgrading GIT to a newer version)",
-                       path);
-       }
+               version = ntohl(hdr->idx_version);
+               if (version < 2 || version > 2) {
+                       munmap(idx_map, idx_size);
+                       return error("index file %s is version %d"
+                                    " and is not supported by this binary"
+                                    " (try upgrading GIT to a newer version)",
+                                    path, version);
+               }
+       } else
+               version = 1;
 
        nr = 0;
        index = idx_map;
+       if (version > 1)
+               index += 2;  /* skip index header */
        for (i = 0; i < 256; i++) {
                uint32_t n = ntohl(index[i]);
                if (n < nr) {
@@ -479,24 +487,72 @@ static int check_packed_git_idx(const char *path,  struct packed_git *p)
                nr = n;
        }
 
-       /*
-        * Total size:
-        *  - 256 index entries 4 bytes each
-        *  - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
-        *  - 20-byte SHA1 of the packfile
-        *  - 20-byte SHA1 file checksum
-        */
-       if (idx_size != 4*256 + nr * 24 + 20 + 20) {
-               munmap(idx_map, idx_size);
-               return error("wrong index file size in %s", path);
+       if (version == 1) {
+               /*
+                * Total size:
+                *  - 256 index entries 4 bytes each
+                *  - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
+                *  - 20-byte SHA1 of the packfile
+                *  - 20-byte SHA1 file checksum
+                */
+               if (idx_size != 4*256 + nr * 24 + 20 + 20) {
+                       munmap(idx_map, idx_size);
+                       return error("wrong index file size in %s", path);
+               }
+       } else if (version == 2) {
+               /*
+                * Minimum size:
+                *  - 8 bytes of header
+                *  - 256 index entries 4 bytes each
+                *  - 20-byte sha1 entry * nr
+                *  - 4-byte crc entry * nr
+                *  - 4-byte offset entry * nr
+                *  - 20-byte SHA1 of the packfile
+                *  - 20-byte SHA1 file checksum
+                * And after the 4-byte offset table might be a
+                * variable sized table containing 8-byte entries
+                * for offsets larger than 2^31.
+                */
+               unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
+               unsigned long max_size = min_size;
+               if (nr)
+                       max_size += (nr - 1)*8;
+               if (idx_size < min_size || idx_size > max_size) {
+                       munmap(idx_map, idx_size);
+                       return error("wrong index file size in %s", path);
+               }
+               if (idx_size != min_size) {
+                       /* make sure we can deal with large pack offsets */
+                       off_t x = 0x7fffffffUL, y = 0xffffffffUL;
+                       if (x > (x + 1) || y > (y + 1)) {
+                               munmap(idx_map, idx_size);
+                               return error("pack too large for current definition of off_t in %s", path);
+                       }
+               }
        }
 
-       p->index_version = 1;
+       p->index_version = version;
        p->index_data = idx_map;
        p->index_size = idx_size;
+       p->num_objects = nr;
        return 0;
 }
 
+int open_pack_index(struct packed_git *p)
+{
+       char *idx_name;
+       int ret;
+
+       if (p->index_data)
+               return 0;
+
+       idx_name = xstrdup(p->pack_name);
+       strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
+       ret = check_packed_git_idx(idx_name, p);
+       free(idx_name);
+       return ret;
+}
+
 static void scan_windows(struct packed_git *p,
        struct packed_git **lru_p,
        struct pack_window **lru_w,
@@ -572,6 +628,9 @@ static int open_packed_git_1(struct packed_git *p)
        unsigned char *idx_sha1;
        long fd_flag;
 
+       if (!p->index_data && open_pack_index(p))
+               return error("packfile %s index unavailable", p->pack_name);
+
        p->pack_fd = open(p->pack_name, O_RDONLY);
        if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
                return -1;
@@ -605,11 +664,11 @@ static int open_packed_git_1(struct packed_git *p)
                        p->pack_name, ntohl(hdr.hdr_version));
 
        /* Verify the pack matches its index. */
-       if (num_packed_objects(p) != ntohl(hdr.hdr_entries))
+       if (p->num_objects != ntohl(hdr.hdr_entries))
                return error("packfile %s claims to have %u objects"
-                       " while index size indicates %u objects",
-                       p->pack_name, ntohl(hdr.hdr_entries),
-                       num_packed_objects(p));
+                            " while index indicates %u objects",
+                            p->pack_name, ntohl(hdr.hdr_entries),
+                            p->num_objects);
        if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
                return error("end of packfile %s is unavailable", p->pack_name);
        if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
@@ -724,8 +783,7 @@ struct packed_git *add_packed_git(const char *path, int path_len, int local)
                return NULL;
        memcpy(p->pack_name, path, path_len);
        strcpy(p->pack_name + path_len, ".pack");
-       if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode) ||
-           check_packed_git_idx(path, p)) {
+       if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
                free(p);
                return NULL;
        }
@@ -733,6 +791,10 @@ struct packed_git *add_packed_git(const char *path, int path_len, int local)
        /* ok, it looks sane as far as we can check without
         * actually mapping the pack file.
         */
+       p->index_version = 0;
+       p->index_data = NULL;
+       p->index_size = 0;
+       p->num_objects = 0;
        p->pack_size = st.st_size;
        p->next = NULL;
        p->windows = NULL;
@@ -778,7 +840,10 @@ void install_packed_git(struct packed_git *pack)
 
 static void prepare_packed_git_one(char *objdir, int local)
 {
-       char path[PATH_MAX];
+       /* Ensure that this buffer is large enough so that we can
+          append "/pack/" without clobbering the stack even if
+          strlen(objdir) were PATH_MAX.  */
+       char path[PATH_MAX + 1 + 4 + 1 + 1];
        int len;
        DIR *dir;
        struct dirent *de;
@@ -800,6 +865,9 @@ static void prepare_packed_git_one(char *objdir, int local)
                if (!has_extension(de->d_name, ".idx"))
                        continue;
 
+               if (len + namelen + 1 > sizeof(path))
+                       continue;
+
                /* Don't reopen a pack we already have. */
                strcpy(path + len, de->d_name);
                for (p = packed_git; p; p = p->next) {
@@ -904,7 +972,7 @@ int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long siz
        return hashcmp(sha1, real_sha1) ? -1 : 0;
 }
 
-void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
+static void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
 {
        struct stat st;
        void *map;
@@ -939,7 +1007,7 @@ void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
        return map;
 }
 
-int legacy_loose_object(unsigned char *map)
+static int legacy_loose_object(unsigned char *map)
 {
        unsigned int word;
 
@@ -1001,6 +1069,14 @@ static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned lon
                return inflate(stream, 0);
        }
 
+
+       /*
+        * There used to be a second loose object header format which
+        * was meant to mimic the in-pack format, allowing for direct
+        * copy of the object data.  This format turned up not to be
+        * really worth it and we don't write it any longer.  But we
+        * can still read it.
+        */
        used = unpack_object_header_gently(map, mapsize, &type, &size);
        if (!used || !valid_loose_object_type[type])
                return -1;
@@ -1076,7 +1152,7 @@ static int parse_sha1_header(const char *hdr, unsigned long *sizep)
        unsigned long size;
 
        /*
-        * The type can be at most ten bytes (including the 
+        * The type can be at most ten bytes (including the
         * terminating '\0' that we add), and is followed by
         * a space.
         */
@@ -1128,6 +1204,43 @@ static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type
        return unpack_sha1_rest(&stream, hdr, *size, sha1);
 }
 
+unsigned long get_size_from_delta(struct packed_git *p,
+                                 struct pack_window **w_curs,
+                                 off_t curpos)
+{
+       const unsigned char *data;
+       unsigned char delta_head[20], *in;
+       z_stream stream;
+       int st;
+
+       memset(&stream, 0, sizeof(stream));
+       stream.next_out = delta_head;
+       stream.avail_out = sizeof(delta_head);
+
+       inflateInit(&stream);
+       do {
+               in = use_pack(p, w_curs, curpos, &stream.avail_in);
+               stream.next_in = in;
+               st = inflate(&stream, Z_FINISH);
+               curpos += stream.next_in - in;
+       } while ((st == Z_OK || st == Z_BUF_ERROR) &&
+                stream.total_out < sizeof(delta_head));
+       inflateEnd(&stream);
+       if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head))
+               die("delta data unpack-initial failed");
+
+       /* Examine the initial part of the delta to figure out
+        * the result size.
+        */
+       data = delta_head;
+
+       /* ignore base size */
+       get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
+
+       /* Read the result size */
+       return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
+}
+
 static off_t get_delta_base(struct packed_git *p,
                                    struct pack_window **w_curs,
                                    off_t *curpos,
@@ -1149,7 +1262,7 @@ static off_t get_delta_base(struct packed_git *p,
                base_offset = c & 127;
                while (c & 128) {
                        base_offset += 1;
-                       if (!base_offset || base_offset & ~(~0UL >> 7))
+                       if (!base_offset || MSB(base_offset, 7))
                                die("offset value overflow for delta base object");
                        c = base_info[used++];
                        base_offset = (base_offset << 7) + (c & 127);
@@ -1191,40 +1304,8 @@ static int packed_delta_info(struct packed_git *p,
         * based on a base with a wrong size.  This saves tons of
         * inflate() calls.
         */
-       if (sizep) {
-               const unsigned char *data;
-               unsigned char delta_head[20], *in;
-               z_stream stream;
-               int st;
-
-               memset(&stream, 0, sizeof(stream));
-               stream.next_out = delta_head;
-               stream.avail_out = sizeof(delta_head);
-
-               inflateInit(&stream);
-               do {
-                       in = use_pack(p, w_curs, curpos, &stream.avail_in);
-                       stream.next_in = in;
-                       st = inflate(&stream, Z_FINISH);
-                       curpos += stream.next_in - in;
-               } while ((st == Z_OK || st == Z_BUF_ERROR)
-                       && stream.total_out < sizeof(delta_head));
-               inflateEnd(&stream);
-               if ((st != Z_STREAM_END) &&
-                   stream.total_out != sizeof(delta_head))
-                       die("delta data unpack-initial failed");
-
-               /* Examine the initial part of the delta to figure out
-                * the result size.
-                */
-               data = delta_head;
-
-               /* ignore base size */
-               get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
-
-               /* Read the result size */
-               *sizep = get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
-       }
+       if (sizep)
+               *sizep = get_size_from_delta(p, w_curs, curpos);
 
        return type;
 }
@@ -1526,38 +1607,71 @@ void *unpack_entry(struct packed_git *p, off_t obj_offset,
        return data;
 }
 
-uint32_t num_packed_objects(const struct packed_git *p)
+const unsigned char *nth_packed_object_sha1(struct packed_git *p,
+                                           uint32_t n)
 {
-       /* See check_packed_git_idx() */
-       return (uint32_t)((p->index_size - 20 - 20 - 4*256) / 24);
+       const unsigned char *index = p->index_data;
+       if (!index) {
+               if (open_pack_index(p))
+                       return NULL;
+               index = p->index_data;
+       }
+       if (n >= p->num_objects)
+               return NULL;
+       index += 4 * 256;
+       if (p->index_version == 1) {
+               return index + 24 * n + 4;
+       } else {
+               index += 8;
+               return index + 20 * n;
+       }
 }
 
-int nth_packed_object_sha1(const struct packed_git *p, uint32_t n,
-                          unsigned char* sha1)
+static off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
 {
        const unsigned char *index = p->index_data;
        index += 4 * 256;
-       if (num_packed_objects(p) <= n)
-               return -1;
-       hashcpy(sha1, index + 24 * n + 4);
-       return 0;
+       if (p->index_version == 1) {
+               return ntohl(*((uint32_t *)(index + 24 * n)));
+       } else {
+               uint32_t off;
+               index += 8 + p->num_objects * (20 + 4);
+               off = ntohl(*((uint32_t *)(index + 4 * n)));
+               if (!(off & 0x80000000))
+                       return off;
+               index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
+               return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
+                                  ntohl(*((uint32_t *)(index + 4)));
+       }
 }
 
 off_t find_pack_entry_one(const unsigned char *sha1,
                                  struct packed_git *p)
 {
        const uint32_t *level1_ofs = p->index_data;
-       int hi = ntohl(level1_ofs[*sha1]);
-       int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
        const unsigned char *index = p->index_data;
+       unsigned hi, lo;
 
+       if (!index) {
+               if (open_pack_index(p))
+                       return 0;
+               level1_ofs = p->index_data;
+               index = p->index_data;
+       }
+       if (p->index_version > 1) {
+               level1_ofs += 2;
+               index += 8;
+       }
        index += 4 * 256;
+       hi = ntohl(level1_ofs[*sha1]);
+       lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
 
        do {
-               int mi = (lo + hi) / 2;
-               int cmp = hashcmp(index + 24 * mi + 4, sha1);
+               unsigned mi = (lo + hi) / 2;
+               unsigned x = (p->index_version > 1) ? (mi * 20) : (mi * 24 + 4);
+               int cmp = hashcmp(index + x, sha1);
                if (!cmp)
-                       return ntohl(*((uint32_t *)((char *)index + (24 * mi))));
+                       return nth_packed_object_offset(p, mi);
                if (cmp > 0)
                        hi = mi;
                else
@@ -1586,20 +1700,25 @@ static int matches_pack_name(struct packed_git *p, const char *ig)
 
 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
 {
+       static struct packed_git *last_found = (void *)1;
        struct packed_git *p;
        off_t offset;
 
        prepare_packed_git();
+       if (!packed_git)
+               return 0;
+       p = (last_found == (void *)1) ? packed_git : last_found;
 
-       for (p = packed_git; p; p = p->next) {
+       do {
                if (ignore_packed) {
                        const char **ig;
                        for (ig = ignore_packed; *ig; ig++)
                                if (!matches_pack_name(p, *ig))
                                        break;
                        if (*ig)
-                               continue;
+                               goto next;
                }
+
                offset = find_pack_entry_one(sha1, p);
                if (offset) {
                        /*
@@ -1612,18 +1731,27 @@ static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, cons
                         */
                        if (p->pack_fd == -1 && open_packed_git(p)) {
                                error("packfile %s cannot be accessed", p->pack_name);
-                               continue;
+                               goto next;
                        }
                        e->offset = offset;
                        e->p = p;
                        hashcpy(e->sha1, sha1);
+                       last_found = p;
                        return 1;
                }
-       }
+
+               next:
+               if (p == last_found)
+                       p = packed_git;
+               else
+                       p = p->next;
+               if (p == last_found)
+                       p = p->next;
+       } while (p);
        return 0;
 }
 
-struct packed_git *find_sha1_pack(const unsigned char *sha1, 
+struct packed_git *find_sha1_pack(const unsigned char *sha1,
                                  struct packed_git *packs)
 {
        struct packed_git *p;
@@ -1902,40 +2030,6 @@ static int write_buffer(int fd, const void *buf, size_t len)
        return 0;
 }
 
-static int write_binary_header(unsigned char *hdr, enum object_type type, unsigned long len)
-{
-       int hdr_len;
-       unsigned char c;
-
-       c = (type << 4) | (len & 15);
-       len >>= 4;
-       hdr_len = 1;
-       while (len) {
-               *hdr++ = c | 0x80;
-               hdr_len++;
-               c = (len & 0x7f);
-               len >>= 7;
-       }
-       *hdr = c;
-       return hdr_len;
-}
-
-static void setup_object_header(z_stream *stream, const char *type, unsigned long len)
-{
-       int obj_type, hdrlen;
-
-       if (use_legacy_headers) {
-               while (deflate(stream, 0) == Z_OK)
-                       /* nothing */;
-               return;
-       }
-       obj_type = type_from_string(type);
-       hdrlen = write_binary_header(stream->next_out, obj_type, len);
-       stream->total_out = hdrlen;
-       stream->next_out += hdrlen;
-       stream->avail_out -= hdrlen;
-}
-
 int hash_sha1_file(const void *buf, unsigned long len, const char *type,
                    unsigned char *sha1)
 {
@@ -2002,7 +2096,8 @@ int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned cha
        /* First header.. */
        stream.next_in = (unsigned char *)hdr;
        stream.avail_in = hdrlen;
-       setup_object_header(&stream, type, len);
+       while (deflate(&stream, 0) == Z_OK)
+               /* nothing */;
 
        /* Then the data itself.. */
        stream.next_in = buf;
@@ -2209,27 +2304,36 @@ int has_sha1_file(const unsigned char *sha1)
  *
  * returns 0 if anything went fine and -1 otherwise
  *
+ * The buffer is always NUL-terminated, not including it in returned size.
+ *
  * NOTE: both buf and size may change, but even when -1 is returned
  * you still have to free() it yourself.
  */
-int read_pipe(int fd, char** return_buf, unsigned long* return_size)
+int read_fd(int fd, char **return_buf, unsigned long *return_size)
 {
-       charbuf = *return_buf;
+       char *buf = *return_buf;
        unsigned long size = *return_size;
-       int iret;
+       ssize_t iret;
        unsigned long off = 0;
 
+       if (!buf || size <= 1) {
+               size = 1024;
+               buf = xrealloc(buf, size);
+       }
+
        do {
-               iret = xread(fd, buf + off, size - off);
+               iret = xread(fd, buf + off, (size - 1) - off);
                if (iret > 0) {
                        off += iret;
-                       if (off == size) {
-                               size *= 2;
+                       if (off == size - 1) {
+                               size = alloc_nr(size);
                                buf = xrealloc(buf, size);
                        }
                }
        } while (iret > 0);
 
+       buf[off] = '\0';
+
        *return_buf = buf;
        *return_size = off;
 
@@ -2244,7 +2348,7 @@ int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
        char *buf = xmalloc(size);
        int ret;
 
-       if (read_pipe(fd, &buf, &size)) {
+       if (read_fd(fd, &buf, &size)) {
                free(buf);
                return -1;
        }
@@ -2278,10 +2382,9 @@ int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
         */
        if ((type == OBJ_BLOB) && S_ISREG(st->st_mode)) {
                unsigned long nsize = size;
-               char *nbuf = buf;
-               if (convert_to_git(path, &nbuf, &nsize)) {
-                       if (size)
-                               munmap(buf, size);
+               char *nbuf = convert_to_git(path, buf, &nsize);
+               if (nbuf) {
+                       munmap(buf, size);
                        size = nsize;
                        buf = nbuf;
                        re_allocated = 1;
@@ -2333,6 +2436,8 @@ int index_path(unsigned char *sha1, const char *path, struct stat *st, int write
                                     path);
                free(target);
                break;
+       case S_IFDIR:
+               return resolve_gitlink_ref(path, "HEAD", sha1);
        default:
                return error("%s: unsupported file type", path);
        }