Merge branch 'rs/p5302-create-repositories-before-tests'
[gitweb.git] / sha1_file.c
index 9c86d1924a23e4c81369f34ec8e1058c2dd15c1f..ec957db5e1c2620b4a95e4f4d028f01794cef02a 100644 (file)
 #include "mru.h"
 #include "list.h"
 #include "mergesort.h"
-
-#ifndef O_NOATIME
-#if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
-#define O_NOATIME 01000000
-#else
-#define O_NOATIME 0
-#endif
-#endif
+#include "quote.h"
 
 #define SZ_FMT PRIuMAX
 static inline uintmax_t sz_fmt(size_t s) { return s; }
@@ -291,7 +284,7 @@ static int link_alt_odb_entry(const char *entry, const char *relative_base,
        struct strbuf pathbuf = STRBUF_INIT;
 
        if (!is_absolute_path(entry) && relative_base) {
-               strbuf_addstr(&pathbuf, real_path(relative_base));
+               strbuf_realpath(&pathbuf, relative_base, 1);
                strbuf_addch(&pathbuf, '/');
        }
        strbuf_addstr(&pathbuf, entry);
@@ -329,13 +322,40 @@ static int link_alt_odb_entry(const char *entry, const char *relative_base,
        return 0;
 }
 
+static const char *parse_alt_odb_entry(const char *string,
+                                      int sep,
+                                      struct strbuf *out)
+{
+       const char *end;
+
+       strbuf_reset(out);
+
+       if (*string == '#') {
+               /* comment; consume up to next separator */
+               end = strchrnul(string, sep);
+       } else if (*string == '"' && !unquote_c_style(out, string, &end)) {
+               /*
+                * quoted path; unquote_c_style has copied the
+                * data for us and set "end". Broken quoting (e.g.,
+                * an entry that doesn't end with a quote) falls
+                * back to the unquoted case below.
+                */
+       } else {
+               /* normal, unquoted path */
+               end = strchrnul(string, sep);
+               strbuf_add(out, string, end - string);
+       }
+
+       if (*end)
+               end++;
+       return end;
+}
+
 static void link_alt_odb_entries(const char *alt, int len, int sep,
                                 const char *relative_base, int depth)
 {
-       struct string_list entries = STRING_LIST_INIT_NODUP;
-       char *alt_copy;
-       int i;
        struct strbuf objdirbuf = STRBUF_INIT;
+       struct strbuf entry = STRBUF_INIT;
 
        if (depth > 5) {
                error("%s: ignoring alternate object stores, nesting too deep.",
@@ -348,16 +368,13 @@ static void link_alt_odb_entries(const char *alt, int len, int sep,
                die("unable to normalize object directory: %s",
                    objdirbuf.buf);
 
-       alt_copy = xmemdupz(alt, len);
-       string_list_split_in_place(&entries, alt_copy, sep, -1);
-       for (i = 0; i < entries.nr; i++) {
-               const char *entry = entries.items[i].string;
-               if (entry[0] == '\0' || entry[0] == '#')
+       while (*alt) {
+               alt = parse_alt_odb_entry(alt, sep, &entry);
+               if (!entry.len)
                        continue;
-               link_alt_odb_entry(entry, relative_base, depth, objdirbuf.buf);
+               link_alt_odb_entry(entry.buf, relative_base, depth, objdirbuf.buf);
        }
-       string_list_clear(&entries, 0);
-       free(alt_copy);
+       strbuf_release(&entry);
        strbuf_release(&objdirbuf);
 }
 
@@ -1586,66 +1603,81 @@ int check_sha1_signature(const unsigned char *sha1, void *map,
        return hashcmp(sha1, real_sha1) ? -1 : 0;
 }
 
-int git_open(const char *name)
+int git_open_cloexec(const char *name, int flags)
 {
-       static int sha1_file_open_flag = O_NOATIME | O_CLOEXEC;
-
-       for (;;) {
-               int fd;
-
-               errno = 0;
-               fd = open(name, O_RDONLY | sha1_file_open_flag);
-               if (fd >= 0)
-                       return fd;
+       int fd;
+       static int o_cloexec = O_CLOEXEC;
 
+       fd = open(name, flags | o_cloexec);
+       if ((o_cloexec & O_CLOEXEC) && fd < 0 && errno == EINVAL) {
                /* Try again w/o O_CLOEXEC: the kernel might not support it */
-               if ((sha1_file_open_flag & O_CLOEXEC) && errno == EINVAL) {
-                       sha1_file_open_flag &= ~O_CLOEXEC;
-                       continue;
-               }
+               o_cloexec &= ~O_CLOEXEC;
+               fd = open(name, flags | o_cloexec);
+       }
 
-               /* Might the failure be due to O_NOATIME? */
-               if (errno != ENOENT && (sha1_file_open_flag & O_NOATIME)) {
-                       sha1_file_open_flag &= ~O_NOATIME;
-                       continue;
+#if defined(F_GETFL) && defined(F_SETFL) && defined(FD_CLOEXEC)
+       {
+               static int fd_cloexec = FD_CLOEXEC;
+
+               if (!o_cloexec && 0 <= fd && fd_cloexec) {
+                       /* Opened w/o O_CLOEXEC?  try with fcntl(2) to add it */
+                       int flags = fcntl(fd, F_GETFL);
+                       if (fcntl(fd, F_SETFL, flags | fd_cloexec))
+                               fd_cloexec = 0;
                }
-               return -1;
        }
+#endif
+       return fd;
 }
 
-static int stat_sha1_file(const unsigned char *sha1, struct stat *st)
+/*
+ * Find "sha1" as a loose object in the local repository or in an alternate.
+ * Returns 0 on success, negative on failure.
+ *
+ * The "path" out-parameter will give the path of the object we found (if any).
+ * Note that it may point to static storage and is only valid until another
+ * call to sha1_file_name(), etc.
+ */
+static int stat_sha1_file(const unsigned char *sha1, struct stat *st,
+                         const char **path)
 {
        struct alternate_object_database *alt;
 
-       if (!lstat(sha1_file_name(sha1), st))
+       *path = sha1_file_name(sha1);
+       if (!lstat(*path, st))
                return 0;
 
        prepare_alt_odb();
        errno = ENOENT;
        for (alt = alt_odb_list; alt; alt = alt->next) {
-               const char *path = alt_sha1_path(alt, sha1);
-               if (!lstat(path, st))
+               *path = alt_sha1_path(alt, sha1);
+               if (!lstat(*path, st))
                        return 0;
        }
 
        return -1;
 }
 
-static int open_sha1_file(const unsigned char *sha1)
+/*
+ * Like stat_sha1_file(), but actually open the object and return the
+ * descriptor. See the caveats on the "path" parameter above.
+ */
+static int open_sha1_file(const unsigned char *sha1, const char **path)
 {
        int fd;
        struct alternate_object_database *alt;
        int most_interesting_errno;
 
-       fd = git_open(sha1_file_name(sha1));
+       *path = sha1_file_name(sha1);
+       fd = git_open(*path);
        if (fd >= 0)
                return fd;
        most_interesting_errno = errno;
 
        prepare_alt_odb();
        for (alt = alt_odb_list; alt; alt = alt->next) {
-               const char *path = alt_sha1_path(alt, sha1);
-               fd = git_open(path);
+               *path = alt_sha1_path(alt, sha1);
+               fd = git_open(*path);
                if (fd >= 0)
                        return fd;
                if (most_interesting_errno == ENOENT)
@@ -1655,12 +1687,21 @@ static int open_sha1_file(const unsigned char *sha1)
        return -1;
 }
 
-void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
+/*
+ * Map the loose object at "path" if it is not NULL, or the path found by
+ * searching for a loose object named "sha1".
+ */
+static void *map_sha1_file_1(const char *path,
+                            const unsigned char *sha1,
+                            unsigned long *size)
 {
        void *map;
        int fd;
 
-       fd = open_sha1_file(sha1);
+       if (path)
+               fd = git_open(path);
+       else
+               fd = open_sha1_file(sha1, &path);
        map = NULL;
        if (fd >= 0) {
                struct stat st;
@@ -1669,7 +1710,7 @@ void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
                        *size = xsize_t(st.st_size);
                        if (!*size) {
                                /* mmap() is forbidden on empty files */
-                               error("object file %s is empty", sha1_file_name(sha1));
+                               error("object file %s is empty", path);
                                return NULL;
                        }
                        map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
@@ -1679,6 +1720,11 @@ void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
        return map;
 }
 
+void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
+{
+       return map_sha1_file_1(NULL, sha1, size);
+}
+
 unsigned long unpack_object_header_buffer(const unsigned char *buf,
                unsigned long len, enum object_type *type, unsigned long *sizep)
 {
@@ -2325,11 +2371,10 @@ static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
 
 void clear_delta_base_cache(void)
 {
-       struct hashmap_iter iter;
-       struct delta_base_cache_entry *entry;
-       for (entry = hashmap_iter_first(&delta_base_cache, &iter);
-            entry;
-            entry = hashmap_iter_next(&iter)) {
+       struct list_head *lru, *tmp;
+       list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
+               struct delta_base_cache_entry *entry =
+                       list_entry(lru, struct delta_base_cache_entry, lru);
                release_delta_base_cache(entry);
        }
 }
@@ -2789,8 +2834,9 @@ static int sha1_loose_object_info(const unsigned char *sha1,
         * object even exists.
         */
        if (!oi->typep && !oi->typename && !oi->sizep) {
+               const char *path;
                struct stat st;
-               if (stat_sha1_file(sha1, &st) < 0)
+               if (stat_sha1_file(sha1, &st, &path) < 0)
                        return -1;
                if (oi->disk_sizep)
                        *oi->disk_sizep = st.st_size;
@@ -2986,6 +3032,8 @@ void *read_sha1_file_extended(const unsigned char *sha1,
 {
        void *data;
        const struct packed_git *p;
+       const char *path;
+       struct stat st;
        const unsigned char *repl = lookup_replace_object_extended(sha1, flag);
 
        errno = 0;
@@ -3001,12 +3049,9 @@ void *read_sha1_file_extended(const unsigned char *sha1,
                die("replacement %s not found for %s",
                    sha1_to_hex(repl), sha1_to_hex(sha1));
 
-       if (has_loose_object(repl)) {
-               const char *path = sha1_file_name(sha1);
-
+       if (!stat_sha1_file(repl, &st, &path))
                die("loose object %s (stored in %s) is corrupt",
                    sha1_to_hex(repl), path);
-       }
 
        if ((p = has_packed_and_bad(repl)) != NULL)
                die("packed object %s (stored in %s) is corrupt",
@@ -3776,3 +3821,122 @@ int for_each_packed_object(each_packed_object_fn cb, void *data, unsigned flags)
        }
        return r ? r : pack_errors;
 }
+
+static int check_stream_sha1(git_zstream *stream,
+                            const char *hdr,
+                            unsigned long size,
+                            const char *path,
+                            const unsigned char *expected_sha1)
+{
+       git_SHA_CTX c;
+       unsigned char real_sha1[GIT_SHA1_RAWSZ];
+       unsigned char buf[4096];
+       unsigned long total_read;
+       int status = Z_OK;
+
+       git_SHA1_Init(&c);
+       git_SHA1_Update(&c, hdr, stream->total_out);
+
+       /*
+        * We already read some bytes into hdr, but the ones up to the NUL
+        * do not count against the object's content size.
+        */
+       total_read = stream->total_out - strlen(hdr) - 1;
+
+       /*
+        * This size comparison must be "<=" to read the final zlib packets;
+        * see the comment in unpack_sha1_rest for details.
+        */
+       while (total_read <= size &&
+              (status == Z_OK || status == Z_BUF_ERROR)) {
+               stream->next_out = buf;
+               stream->avail_out = sizeof(buf);
+               if (size - total_read < stream->avail_out)
+                       stream->avail_out = size - total_read;
+               status = git_inflate(stream, Z_FINISH);
+               git_SHA1_Update(&c, buf, stream->next_out - buf);
+               total_read += stream->next_out - buf;
+       }
+       git_inflate_end(stream);
+
+       if (status != Z_STREAM_END) {
+               error("corrupt loose object '%s'", sha1_to_hex(expected_sha1));
+               return -1;
+       }
+       if (stream->avail_in) {
+               error("garbage at end of loose object '%s'",
+                     sha1_to_hex(expected_sha1));
+               return -1;
+       }
+
+       git_SHA1_Final(real_sha1, &c);
+       if (hashcmp(expected_sha1, real_sha1)) {
+               error("sha1 mismatch for %s (expected %s)", path,
+                     sha1_to_hex(expected_sha1));
+               return -1;
+       }
+
+       return 0;
+}
+
+int read_loose_object(const char *path,
+                     const unsigned char *expected_sha1,
+                     enum object_type *type,
+                     unsigned long *size,
+                     void **contents)
+{
+       int ret = -1;
+       int fd = -1;
+       void *map = NULL;
+       unsigned long mapsize;
+       git_zstream stream;
+       char hdr[32];
+
+       *contents = NULL;
+
+       map = map_sha1_file_1(path, NULL, &mapsize);
+       if (!map) {
+               error_errno("unable to mmap %s", path);
+               goto out;
+       }
+
+       if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0) {
+               error("unable to unpack header of %s", path);
+               goto out;
+       }
+
+       *type = parse_sha1_header(hdr, size);
+       if (*type < 0) {
+               error("unable to parse header of %s", path);
+               git_inflate_end(&stream);
+               goto out;
+       }
+
+       if (*type == OBJ_BLOB) {
+               if (check_stream_sha1(&stream, hdr, *size, path, expected_sha1) < 0)
+                       goto out;
+       } else {
+               *contents = unpack_sha1_rest(&stream, hdr, *size, expected_sha1);
+               if (!*contents) {
+                       error("unable to unpack contents of %s", path);
+                       git_inflate_end(&stream);
+                       goto out;
+               }
+               if (check_sha1_signature(expected_sha1, *contents,
+                                        *size, typename(*type))) {
+                       error("sha1 mismatch for %s (expected %s)", path,
+                             sha1_to_hex(expected_sha1));
+                       free(*contents);
+                       goto out;
+               }
+       }
+
+       ret = 0; /* everything checks out */
+
+out:
+       if (map)
+               munmap(map, mapsize);
+       if (fd >= 0)
+               close(fd);
+       return ret;
+}