Add CVS import scripts and programs
[gitweb.git] / sha1_file.c
index 6f7228e106d4e24b18f8416cc6adc2a6fd303eb7..7cfd43c51ba20ee85fe6056c67bbc88cc90dad81 100644 (file)
@@ -6,10 +6,18 @@
  * This handles basic git sha1 object files - packing, unpacking,
  * creation etc.
  */
-#include <stdarg.h>
 #include "cache.h"
+#include "delta.h"
 
-const char *sha1_file_directory = NULL;
+#ifndef O_NOATIME
+#if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
+#define O_NOATIME 01000000
+#else
+#define O_NOATIME 0
+#endif
+#endif
+
+static unsigned int sha1_file_open_flag = O_NOATIME;
 
 static unsigned hexval(char c)
 {
@@ -35,6 +43,90 @@ int get_sha1_hex(const char *hex, unsigned char *sha1)
        return 0;
 }
 
+static int get_sha1_file(const char *path, unsigned char *result)
+{
+       char buffer[60];
+       int fd = open(path, O_RDONLY);
+       int len;
+
+       if (fd < 0)
+               return -1;
+       len = read(fd, buffer, sizeof(buffer));
+       close(fd);
+       if (len < 40)
+               return -1;
+       return get_sha1_hex(buffer, result);
+}
+
+static char *git_dir, *git_object_dir, *git_index_file, *git_refs_dir;
+static void setup_git_env(void)
+{
+       git_dir = gitenv(GIT_DIR_ENVIRONMENT);
+       if (!git_dir)
+               git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
+       git_object_dir = gitenv(DB_ENVIRONMENT);
+       if (!git_object_dir) {
+               git_object_dir = xmalloc(strlen(git_dir) + 9);
+               sprintf(git_object_dir, "%s/objects", git_dir);
+       }
+       git_refs_dir = xmalloc(strlen(git_dir) + 6);
+       sprintf(git_refs_dir, "%s/refs", git_dir);
+       git_index_file = gitenv(INDEX_ENVIRONMENT);
+       if (!git_index_file) {
+               git_index_file = xmalloc(strlen(git_dir) + 7);
+               sprintf(git_index_file, "%s/index", git_dir);
+       }
+}
+
+char *get_object_directory(void)
+{
+       if (!git_object_dir)
+               setup_git_env();
+       return git_object_dir;
+}
+
+char *get_refs_directory(void)
+{
+       if (!git_refs_dir)
+               setup_git_env();
+       return git_refs_dir;
+}
+
+char *get_index_file(void)
+{
+       if (!git_index_file)
+               setup_git_env();
+       return git_index_file;
+}
+
+int get_sha1(const char *str, unsigned char *sha1)
+{
+       static char pathname[PATH_MAX];
+       static const char *prefix[] = {
+               "",
+               "refs",
+               "refs/tags",
+               "refs/heads",
+               "refs/snap",
+               NULL
+       };
+       const char **p;
+
+       if (!get_sha1_hex(str, sha1))
+               return 0;
+
+       if (!git_dir)
+               setup_git_env();
+       for (p = prefix; *p; p++) {
+               snprintf(pathname, sizeof(pathname), "%s/%s/%s",
+                        git_dir, *p, str);
+               if (!get_sha1_file(pathname, sha1))
+                       return 0;
+       }
+
+       return -1;
+}
+
 char * sha1_to_hex(const unsigned char *sha1)
 {
        static char buffer[50];
@@ -50,36 +142,130 @@ char * sha1_to_hex(const unsigned char *sha1)
        return buffer;
 }
 
+static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
+{
+       int i;
+       for (i = 0; i < 20; i++) {
+               static char hex[] = "0123456789abcdef";
+               unsigned int val = sha1[i];
+               char *pos = pathbuf + i*2 + (i > 0);
+               *pos++ = hex[val >> 4];
+               *pos = hex[val & 0xf];
+       }
+}
+
 /*
  * NOTE! This returns a statically allocated buffer, so you have to be
  * careful about using it. Do a "strdup()" if you need to save the
  * filename.
+ *
+ * Also note that this returns the location for creating.  Reading
+ * SHA1 file can happen from any alternate directory listed in the
+ * DB_ENVIRONMENT environment variable if it is not found in
+ * the primary object database.
  */
 char *sha1_file_name(const unsigned char *sha1)
 {
-       int i;
        static char *name, *base;
 
        if (!base) {
-               char *sha1_file_directory = getenv(DB_ENVIRONMENT) ? : DEFAULT_DB_ENVIRONMENT;
+               const char *sha1_file_directory = get_object_directory();
                int len = strlen(sha1_file_directory);
-               base = malloc(len + 60);
+               base = xmalloc(len + 60);
                memcpy(base, sha1_file_directory, len);
                memset(base+len, 0, 60);
                base[len] = '/';
                base[len+3] = '/';
                name = base + len + 1;
        }
-       for (i = 0; i < 20; i++) {
-               static char hex[] = "0123456789abcdef";
-               unsigned int val = sha1[i];
-               char *pos = name + i*2 + (i > 0);
-               *pos++ = hex[val >> 4];
-               *pos = hex[val & 0xf];
-       }
+       fill_sha1_path(name, sha1);
        return base;
 }
 
+static struct alternate_object_database {
+       char *base;
+       char *name;
+} *alt_odb;
+
+/*
+ * Prepare alternate object database registry.
+ * alt_odb points at an array of struct alternate_object_database.
+ * This array is terminated with an element that has both its base
+ * and name set to NULL.  alt_odb[n] comes from n'th non-empty
+ * element from colon separated ALTERNATE_DB_ENVIRONMENT environment
+ * variable, and its base points at a statically allocated buffer
+ * that contains "/the/directory/corresponding/to/.git/objects/...",
+ * while its name points just after the slash at the end of
+ * ".git/objects/" in the example above, and has enough space to hold
+ * 40-byte hex SHA1, an extra slash for the first level indirection,
+ * and the terminating NUL.
+ * This function allocates the alt_odb array and all the strings
+ * pointed by base fields of the array elements with one xmalloc();
+ * the string pool immediately follows the array.
+ */
+static void prepare_alt_odb(void)
+{
+       int pass, totlen, i;
+       const char *cp, *last;
+       char *op = NULL;
+       const char *alt = gitenv(ALTERNATE_DB_ENVIRONMENT) ? : "";
+
+       /* The first pass counts how large an area to allocate to
+        * hold the entire alt_odb structure, including array of
+        * structs and path buffers for them.  The second pass fills
+        * the structure and prepares the path buffers for use by
+        * fill_sha1_path().
+        */
+       for (totlen = pass = 0; pass < 2; pass++) {
+               last = alt;
+               i = 0;
+               do {
+                       cp = strchr(last, ':') ? : last + strlen(last);
+                       if (last != cp) {
+                               /* 43 = 40-byte + 2 '/' + terminating NUL */
+                               int pfxlen = cp - last;
+                               int entlen = pfxlen + 43;
+                               if (pass == 0)
+                                       totlen += entlen;
+                               else {
+                                       alt_odb[i].base = op;
+                                       alt_odb[i].name = op + pfxlen + 1;
+                                       memcpy(op, last, pfxlen);
+                                       op[pfxlen] = op[pfxlen + 3] = '/';
+                                       op[entlen-1] = 0;
+                                       op += entlen;
+                               }
+                               i++;
+                       }
+                       while (*cp && *cp == ':')
+                               cp++;
+                       last = cp;
+               } while (*cp);
+               if (pass)
+                       break;
+               alt_odb = xmalloc(sizeof(*alt_odb) * (i + 1) + totlen);
+               alt_odb[i].base = alt_odb[i].name = NULL;
+               op = (char*)(&alt_odb[i+1]);
+       }
+}
+
+static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
+{
+       int i;
+       char *name = sha1_file_name(sha1);
+
+       if (!stat(name, st))
+               return name;
+       if (!alt_odb)
+               prepare_alt_odb();
+       for (i = 0; (name = alt_odb[i].name) != NULL; i++) {
+               fill_sha1_path(name, sha1);
+               if (!stat(alt_odb[i].base, st))
+                       return alt_odb[i].base;
+       }
+       return NULL;
+}
+
 int check_sha1_signature(unsigned char *sha1, void *map, unsigned long size, const char *type)
 {
        char header[100];
@@ -95,18 +281,32 @@ int check_sha1_signature(unsigned char *sha1, void *map, unsigned long size, con
 
 void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
 {
-       char *filename = sha1_file_name(sha1);
-       int fd = open(filename, O_RDONLY);
        struct stat st;
        void *map;
+       int fd;
+       char *filename = find_sha1_file(sha1, &st);
 
-       if (fd < 0) {
-               perror(filename);
+       if (!filename) {
+               error("cannot map sha1 file %s", sha1_to_hex(sha1));
                return NULL;
        }
-       if (fstat(fd, &st) < 0) {
-               close(fd);
-               return NULL;
+
+       fd = open(filename, O_RDONLY | sha1_file_open_flag);
+       if (fd < 0) {
+               /* See if it works without O_NOATIME */
+               switch (sha1_file_open_flag) {
+               default:
+                       fd = open(filename, O_RDONLY);
+                       if (fd >= 0)
+                               break;
+               /* Fallthrough */
+               case 0:
+                       perror(filename);
+                       return NULL;
+               }
+
+               /* If it failed once, it will probably fail again. Stop using O_NOATIME */
+               sha1_file_open_flag = 0;
        }
        map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
        close(fd);
@@ -116,40 +316,189 @@ void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
        return map;
 }
 
+int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size)
+{
+       /* Get the data stream */
+       memset(stream, 0, sizeof(*stream));
+       stream->next_in = map;
+       stream->avail_in = mapsize;
+       stream->next_out = buffer;
+       stream->avail_out = size;
+
+       inflateInit(stream);
+       return inflate(stream, 0);
+}
+
+void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
+{
+       int bytes = strlen(buffer) + 1;
+       char *buf = xmalloc(1+size);
+
+       memcpy(buf, buffer + bytes, stream->total_out - bytes);
+       bytes = stream->total_out - bytes;
+       if (bytes < size) {
+               stream->next_out = buf + bytes;
+               stream->avail_out = size - bytes;
+               while (inflate(stream, Z_FINISH) == Z_OK)
+                       /* nothing */;
+       }
+       buf[size] = 0;
+       inflateEnd(stream);
+       return buf;
+}
+
+/*
+ * We used to just use "sscanf()", but that's actually way
+ * too permissive for what we want to check. So do an anal
+ * object header parse by hand.
+ */
+int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
+{
+       int i;
+       unsigned long size;
+
+       /*
+        * The type can be at most ten bytes (including the 
+        * terminating '\0' that we add), and is followed by
+        * a space. 
+        */
+       i = 10;
+       for (;;) {
+               char c = *hdr++;
+               if (c == ' ')
+                       break;
+               if (!--i)
+                       return -1;
+               *type++ = c;
+       }
+       *type = 0;
+
+       /*
+        * The length must follow immediately, and be in canonical
+        * decimal format (ie "010" is not valid).
+        */
+       size = *hdr++ - '0';
+       if (size > 9)
+               return -1;
+       if (size) {
+               for (;;) {
+                       unsigned long c = *hdr - '0';
+                       if (c > 9)
+                               break;
+                       hdr++;
+                       size = size * 10 + c;
+               }
+       }
+       *sizep = size;
+
+       /*
+        * The length must be followed by a zero byte
+        */
+       return *hdr ? -1 : 0;
+}
+
 void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
 {
-       int ret, bytes;
+       int ret;
        z_stream stream;
-       char buffer[8192];
-       char *buf;
+       char hdr[8192];
 
-       /* Get the data stream */
-       memset(&stream, 0, sizeof(stream));
-       stream.next_in = map;
-       stream.avail_in = mapsize;
-       stream.next_out = buffer;
-       stream.avail_out = sizeof(buffer);
-
-       inflateInit(&stream);
-       ret = inflate(&stream, 0);
-       if (sscanf(buffer, "%10s %lu", type, size) != 2)
+       ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
+       if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
                return NULL;
 
-       bytes = strlen(buffer) + 1;
-       buf = malloc(*size);
-       if (!buf)
-               return NULL;
+       return unpack_sha1_rest(&stream, hdr, *size);
+}
 
-       memcpy(buf, buffer + bytes, stream.total_out - bytes);
-       bytes = stream.total_out - bytes;
-       if (bytes < *size && ret == Z_OK) {
-               stream.next_out = buf + bytes;
-               stream.avail_out = *size - bytes;
-               while (inflate(&stream, Z_FINISH) == Z_OK)
-                       /* nothing */;
+int sha1_delta_base(const unsigned char *sha1, unsigned char *base_sha1)
+{
+       int ret;
+       unsigned long mapsize, size;
+       void *map;
+       z_stream stream;
+       char hdr[64], type[20];
+       void *delta_data_head;
+
+       map = map_sha1_file(sha1, &mapsize);
+       if (!map)
+               return -1;
+       ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
+       if (ret < Z_OK || parse_sha1_header(hdr, type, &size) < 0) {
+               ret = -1;
+               goto out;
+       }
+       if (strcmp(type, "delta")) {
+               ret = 0;
+               goto out;
        }
+
+       delta_data_head = hdr + strlen(hdr) + 1;
+       ret = 1;
+       memcpy(base_sha1, delta_data_head, 20);
+ out:
        inflateEnd(&stream);
-       return buf;
+       munmap(map, mapsize);
+       return ret;
+}
+
+int sha1_file_size(const unsigned char *sha1, unsigned long *sizep)
+{
+       int ret, status;
+       unsigned long mapsize, size;
+       void *map;
+       z_stream stream;
+       char hdr[64], type[20];
+       const unsigned char *data;
+       unsigned char cmd;
+       int i;
+
+       map = map_sha1_file(sha1, &mapsize);
+       if (!map)
+               return -1;
+       ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
+       status = -1;
+       if (ret < Z_OK || parse_sha1_header(hdr, type, &size) < 0)
+               goto out;
+       if (strcmp(type, "delta")) {
+               *sizep = size;
+               status = 0;
+               goto out;
+       }
+
+       /* We are dealing with a delta object.  Inflated, the first
+        * 20 bytes hold the base object SHA1, and delta data follows
+        * immediately after it.
+        *
+        * The initial part of the delta starts at delta_data_head +
+        * 20.  Borrow code from patch-delta to read the result size.
+        */
+       data = hdr + strlen(hdr) + 1 + 20;
+
+       /* Skip over the source size; we are not interested in
+        * it and we cannot verify it because we do not want
+        * to read the base object.
+        */
+       cmd = *data++;
+       while (cmd) {
+               if (cmd & 1)
+                       data++;
+               cmd >>= 1;
+       }
+       /* Read the result size */
+       size = i = 0;
+       cmd = *data++;
+       while (cmd) {
+               if (cmd & 1)
+                       size |= *data++ << i;
+               i += 8;
+               cmd >>= 1;
+       }
+       *sizep = size;
+       status = 0;
+ out:
+       inflateEnd(&stream);
+       munmap(map, mapsize);
+       return status;
 }
 
 void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
@@ -161,63 +510,87 @@ void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size
        if (map) {
                buf = unpack_sha1_file(map, mapsize, type, size);
                munmap(map, mapsize);
+               if (buf && !strcmp(type, "delta")) {
+                       void *ref = NULL, *delta = buf;
+                       unsigned long ref_size, delta_size = *size;
+                       buf = NULL;
+                       if (delta_size > 20)
+                               ref = read_sha1_file(delta, type, &ref_size);
+                       if (ref)
+                               buf = patch_delta(ref, ref_size,
+                                                 delta+20, delta_size-20, 
+                                                 size);
+                       free(delta);
+                       free(ref);
+               }
                return buf;
        }
        return NULL;
 }
 
-void *read_tree_with_tree_or_commit_sha1(const unsigned char *sha1,
-                                        unsigned long *size,
-                                        unsigned char *tree_sha1_return)
+void *read_object_with_reference(const unsigned char *sha1,
+                                const char *required_type,
+                                unsigned long *size,
+                                unsigned char *actual_sha1_return)
 {
        char type[20];
        void *buffer;
        unsigned long isize;
-       int was_commit = 0;
-       unsigned char tree_sha1[20];
-
-       buffer = read_sha1_file(sha1, type, &isize);
-
-       /* 
-        * We might have read a commit instead of a tree, in which case
-        * we parse out the tree_sha1 and attempt to read from there.
-        * (buffer + 5) is because the tree sha1 is always at offset 5
-        * in a commit record ("tree ").
-        */
-       if (buffer &&
-           !strcmp(type, "commit") &&
-           !get_sha1_hex(buffer + 5, tree_sha1)) {
-               free(buffer);
-               buffer = read_sha1_file(tree_sha1, type, &isize);
-               was_commit = 1;
-       }
-
-       /*
-        * Now do we have something and if so is it a tree?
-        */
-       if (!buffer || strcmp(type, "tree")) {
-               free(buffer);
-               return NULL;
+       unsigned char actual_sha1[20];
+
+       memcpy(actual_sha1, sha1, 20);
+       while (1) {
+               int ref_length = -1;
+               const char *ref_type = NULL;
+
+               buffer = read_sha1_file(actual_sha1, type, &isize);
+               if (!buffer)
+                       return NULL;
+               if (!strcmp(type, required_type)) {
+                       *size = isize;
+                       if (actual_sha1_return)
+                               memcpy(actual_sha1_return, actual_sha1, 20);
+                       return buffer;
+               }
+               /* Handle references */
+               else if (!strcmp(type, "commit"))
+                       ref_type = "tree ";
+               else if (!strcmp(type, "tag"))
+                       ref_type = "object ";
+               else {
+                       free(buffer);
+                       return NULL;
+               }
+               ref_length = strlen(ref_type);
+
+               if (memcmp(buffer, ref_type, ref_length) ||
+                   get_sha1_hex(buffer + ref_length, actual_sha1)) {
+                       free(buffer);
+                       return NULL;
+               }
+               /* Now we have the ID of the referred-to object in
+                * actual_sha1.  Check again. */
        }
-
-       *size = isize;
-       if (tree_sha1_return)
-               memcpy(tree_sha1_return, was_commit ? tree_sha1 : sha1, 20);
-       return buffer;
 }
 
-int write_sha1_file(char *buf, unsigned len, unsigned char *returnsha1)
+int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
 {
        int size;
-       char *compressed;
+       unsigned char *compressed;
        z_stream stream;
        unsigned char sha1[20];
        SHA_CTX c;
        char *filename;
-       int fd;
+       static char tmpfile[PATH_MAX];
+       unsigned char hdr[50];
+       int fd, hdrlen, ret;
+
+       /* Generate the header */
+       hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
 
        /* Sha1.. */
        SHA1_Init(&c);
+       SHA1_Update(&c, hdr, hdrlen);
        SHA1_Update(&c, buf, len);
        SHA1_Final(sha1, &c);
 
@@ -225,29 +598,48 @@ int write_sha1_file(char *buf, unsigned len, unsigned char *returnsha1)
                memcpy(returnsha1, sha1, 20);
 
        filename = sha1_file_name(sha1);
-       fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
-       if (fd < 0) {
-               if (errno != EEXIST)
-                       return -1;
-
+       fd = open(filename, O_RDONLY);
+       if (fd >= 0) {
                /*
-                * We might do collision checking here, but we'd need to
-                * uncompress the old file and check it. Later.
+                * FIXME!!! We might do collision checking here, but we'd
+                * need to uncompress the old file and check it. Later.
                 */
+               close(fd);
                return 0;
        }
 
+       if (errno != ENOENT) {
+               fprintf(stderr, "sha1 file %s: %s", filename, strerror(errno));
+               return -1;
+       }
+
+       snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
+
+       fd = mkstemp(tmpfile);
+       if (fd < 0) {
+               fprintf(stderr, "unable to create temporary sha1 filename %s: %s", tmpfile, strerror(errno));
+               return -1;
+       }
+
        /* Set it up */
        memset(&stream, 0, sizeof(stream));
        deflateInit(&stream, Z_BEST_COMPRESSION);
-       size = deflateBound(&stream, len);
-       compressed = malloc(size);
+       size = deflateBound(&stream, len+hdrlen);
+       compressed = xmalloc(size);
 
        /* Compress it */
-       stream.next_in = buf;
-       stream.avail_in = len;
        stream.next_out = compressed;
        stream.avail_out = size;
+
+       /* First header.. */
+       stream.next_in = hdr;
+       stream.avail_in = hdrlen;
+       while (deflate(&stream, 0) == Z_OK)
+               /* nothing */;
+
+       /* Then the data itself.. */
+       stream.next_in = buf;
+       stream.avail_in = len;
        while (deflate(&stream, Z_FINISH) == Z_OK)
                /* nothing */;
        deflateEnd(&stream);
@@ -255,53 +647,121 @@ int write_sha1_file(char *buf, unsigned len, unsigned char *returnsha1)
 
        if (write(fd, compressed, size) != size)
                die("unable to write file");
+       fchmod(fd, 0444);
        close(fd);
-               
+       free(compressed);
+
+       ret = link(tmpfile, filename);
+       if (ret < 0) {
+               ret = errno;
+
+               /*
+                * Coda hack - coda doesn't like cross-directory links,
+                * so we fall back to a rename, which will mean that it
+                * won't be able to check collisions, but that's not a
+                * big deal.
+                *
+                * When this succeeds, we just return 0. We have nothing
+                * left to unlink.
+                */
+               if (ret == EXDEV && !rename(tmpfile, filename))
+                       return 0;
+       }
+       unlink(tmpfile);
+       if (ret) {
+               if (ret != EEXIST) {
+                       fprintf(stderr, "unable to write sha1 filename %s: %s", filename, strerror(ret));
+                       return -1;
+               }
+               /* FIXME!!! Collision check here ? */
+       }
+
        return 0;
 }
 
-static inline int collision_check(char *filename, void *buf, unsigned int size)
+int write_sha1_from_fd(const unsigned char *sha1, int fd)
 {
-#ifdef COLLISION_CHECK
-       void *map;
-       int fd = open(filename, O_RDONLY);
-       struct stat st;
-       int cmp;
+       char *filename = sha1_file_name(sha1);
 
-       /* Unreadable object, or object went away? Strange. */
-       if (fd < 0)
-               return -1;
+       int local;
+       z_stream stream;
+       unsigned char real_sha1[20];
+       unsigned char buf[4096];
+       unsigned char discard[4096];
+       int ret;
+       SHA_CTX c;
 
-       if (fstat(fd, &st) < 0 || size != st.st_size)
-               return -1;
+       local = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
 
-       map = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
-       close(fd);
-       if (map == MAP_FAILED)
-               return -1;
-       cmp = memcmp(buf, map, size);
-       munmap(map, size);
-       if (cmp)
-               return -1;
-#endif
+       if (local < 0)
+               return error("Couldn't open %s\n", filename);
+
+       memset(&stream, 0, sizeof(stream));
+
+       inflateInit(&stream);
+
+       SHA1_Init(&c);
+
+       do {
+               ssize_t size;
+               size = read(fd, buf, 4096);
+               if (size <= 0) {
+                       close(local);
+                       unlink(filename);
+                       if (!size)
+                               return error("Connection closed?");
+                       perror("Reading from connection");
+                       return -1;
+               }
+               write(local, buf, size);
+               stream.avail_in = size;
+               stream.next_in = buf;
+               do {
+                       stream.next_out = discard;
+                       stream.avail_out = sizeof(discard);
+                       ret = inflate(&stream, Z_SYNC_FLUSH);
+                       SHA1_Update(&c, discard, sizeof(discard) -
+                                   stream.avail_out);
+               } while (stream.avail_in && ret == Z_OK);
+               
+       } while (ret == Z_OK);
+       inflateEnd(&stream);
+
+       close(local);
+       SHA1_Final(real_sha1, &c);
+       if (ret != Z_STREAM_END) {
+               unlink(filename);
+               return error("File %s corrupted", sha1_to_hex(sha1));
+       }
+       if (memcmp(sha1, real_sha1, 20)) {
+               unlink(filename);
+               return error("File %s has bad hash\n", sha1_to_hex(sha1));
+       }
+       
        return 0;
 }
 
-int write_sha1_buffer(const unsigned char *sha1, void *buf, unsigned int size)
+int has_sha1_file(const unsigned char *sha1)
 {
-       char *filename = sha1_file_name(sha1);
-       int fd;
+       struct stat st;
+       return !!find_sha1_file(sha1, &st);
+}
 
-       fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
-       if (fd < 0) {
-               if (errno != EEXIST)
-                       return -1;
-               if (collision_check(filename, buf, size))
-                       return error("SHA1 collision detected!"
-                                       " This is bad, bad, BAD!\a\n");
-               return 0;
-       }
-       write(fd, buf, size);
+int index_fd(unsigned char *sha1, int fd, struct stat *st)
+{
+       unsigned long size = st->st_size;
+       void *buf;
+       int ret;
+
+       buf = "";
+       if (size)
+               buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
        close(fd);
-       return 0;
+       if ((int)(long)buf == -1)
+               return -1;
+
+       ret = write_sha1_file(buf, size, "blob", sha1);
+       if (size)
+               munmap(buf, size);
+       return ret;
 }