Merge branch 'sp/mmap'
authorJunio C Hamano <junkio@cox.net>
Sun, 7 Jan 2007 08:12:47 +0000 (00:12 -0800)
committerJunio C Hamano <junkio@cox.net>
Sun, 7 Jan 2007 08:12:47 +0000 (00:12 -0800)
* sp/mmap: (27 commits)
Spell default packedgitlimit slightly differently
Increase packedGit{Limit,WindowSize} on 64 bit systems.
Update packedGit config option documentation.
mmap: set FD_CLOEXEC for file descriptors we keep open for mmap()
pack-objects: fix use of use_pack().
Fix random segfaults in pack-objects.
Cleanup read_cache_from error handling.
Replace mmap with xmmap, better handling MAP_FAILED.
Release pack windows before reporting out of memory.
Default core.packdGitWindowSize to 1 MiB if NO_MMAP.
Test suite for sliding window mmap implementation.
Create pack_report() as a debugging aid.
Support unmapping windows on 'temporary' packfiles.
Improve error message when packfile mmap fails.
Ensure core.packedGitWindowSize cannot be less than 2 pages.
Load core configuration in git-verify-pack.
Fully activate the sliding window pack access.
Unmap individual windows rather than entire files.
Document why header parsing won't exceed a window.
Loop over pack_windows when inflating/accessing data.
...

Conflicts:

cache.h
pack-check.c

14 files changed:
Documentation/config.txt
builtin-pack-objects.c
builtin-verify-pack.c
cache.h
config.c
diff.c
environment.c
git-compat-util.h
pack-check.c
read-cache.c
refs.c
sha1_file.c
t/t5301-sliding-window.sh [new file with mode: 0755]
write_or_die.c
index 4318bf9334d22541b741b4be3fe0315f0e1480e9..b4aae0d0aeba86e995b37a5fe3ab7ec61e268687 100644 (file)
@@ -118,6 +118,34 @@ core.legacyheaders::
        database directly (where the "http://" and "rsync://" protocols
        count as direct access).
 
+core.packedGitWindowSize::
+       Number of bytes of a pack file to map into memory in a
+       single mapping operation.  Larger window sizes may allow
+       your system to process a smaller number of large pack files
+       more quickly.  Smaller window sizes will negatively affect
+       performance due to increased calls to the operating system's
+       memory manager, but may improve performance when accessing
+       a large number of large pack files.
++
+Default is 1 MiB if NO_MMAP was set at compile time, otherwise 32
+MiB on 32 bit platforms and 1 GiB on 64 bit platforms.  This should
+be reasonable for all users/operating systems.  You probably do
+not need to adjust this value.
++
+Common unit suffixes of 'k', 'm', or 'g' are supported.
+
+core.packedGitLimit::
+       Maximum number of bytes to map simultaneously into memory
+       from pack files.  If Git needs to access more than this many
+       bytes at once to complete an operation it will unmap existing
+       regions to reclaim virtual address space within the process.
++
+Default is 256 MiB on 32 bit platforms and 8 GiB on 64 bit platforms.
+This should be reasonable for all users/operating systems, except on
+the largest projects.  You probably do not need to adjust this value.
++
+Common unit suffixes of 'k', 'm', or 'g' are supported.
+
 alias.*::
        Command aliases for the gitlink:git[1] command wrapper - e.g.
        after defining "alias.last = cat-file commit HEAD", the invocation
index 9e15beb3ba1e66987bd1fec51ed864414ffbf07c..42dd8c87a255b81fcc6306ba1ef4bb01dd8dce90 100644 (file)
@@ -276,7 +276,52 @@ static int encode_header(enum object_type type, unsigned long size, unsigned cha
  * we are going to reuse the existing object data as is.  make
  * sure it is not corrupt.
  */
-static int check_inflate(unsigned char *data, unsigned long len, unsigned long expect)
+static int check_pack_inflate(struct packed_git *p,
+               struct pack_window **w_curs,
+               unsigned long offset,
+               unsigned long len,
+               unsigned long expect)
+{
+       z_stream stream;
+       unsigned char fakebuf[4096], *in;
+       int st;
+
+       memset(&stream, 0, sizeof(stream));
+       inflateInit(&stream);
+       do {
+               in = use_pack(p, w_curs, offset, &stream.avail_in);
+               stream.next_in = in;
+               stream.next_out = fakebuf;
+               stream.avail_out = sizeof(fakebuf);
+               st = inflate(&stream, Z_FINISH);
+               offset += stream.next_in - in;
+       } while (st == Z_OK || st == Z_BUF_ERROR);
+       inflateEnd(&stream);
+       return (st == Z_STREAM_END &&
+               stream.total_out == expect &&
+               stream.total_in == len) ? 0 : -1;
+}
+
+static void copy_pack_data(struct sha1file *f,
+               struct packed_git *p,
+               struct pack_window **w_curs,
+               unsigned long offset,
+               unsigned long len)
+{
+       unsigned char *in;
+       unsigned int avail;
+
+       while (len) {
+               in = use_pack(p, w_curs, offset, &avail);
+               if (avail > len)
+                       avail = len;
+               sha1write(f, in, avail);
+               offset += avail;
+               len -= avail;
+       }
+}
+
+static int check_loose_inflate(unsigned char *data, unsigned long len, unsigned long expect)
 {
        z_stream stream;
        unsigned char fakebuf[4096];
@@ -323,7 +368,7 @@ static int revalidate_loose_object(struct object_entry *entry,
                return -1;
        map += used;
        mapsize -= used;
-       return check_inflate(map, mapsize, size);
+       return check_loose_inflate(map, mapsize, size);
 }
 
 static unsigned long write_object(struct sha1file *f,
@@ -416,6 +461,8 @@ static unsigned long write_object(struct sha1file *f,
        }
        else {
                struct packed_git *p = entry->in_pack;
+               struct pack_window *w_curs = NULL;
+               unsigned long offset;
 
                if (entry->delta) {
                        obj_type = (allow_ofs_delta && entry->delta->offset) ?
@@ -437,16 +484,14 @@ static unsigned long write_object(struct sha1file *f,
                        hdrlen += 20;
                }
 
-               use_packed_git(p);
-               buf = (char *) p->pack_base
-                       + entry->in_pack_offset
-                       + entry->in_pack_header_size;
+               offset = entry->in_pack_offset + entry->in_pack_header_size;
                datalen = find_packed_object_size(p, entry->in_pack_offset)
                                - entry->in_pack_header_size;
-               if (!pack_to_stdout && check_inflate(buf, datalen, entry->size))
+               if (!pack_to_stdout && check_pack_inflate(p, &w_curs,
+                               offset, datalen, entry->size))
                        die("corrupt delta in pack %s", sha1_to_hex(entry->sha1));
-               sha1write(f, buf, datalen);
-               unuse_packed_git(p);
+               copy_pack_data(f, p, &w_curs, offset, datalen);
+               unuse_pack(&w_curs);
                reused++;
        }
        if (entry->delta)
@@ -937,22 +982,19 @@ static void check_object(struct object_entry *entry)
 
        if (entry->in_pack && !entry->preferred_base) {
                struct packed_git *p = entry->in_pack;
+               struct pack_window *w_curs = NULL;
                unsigned long left = p->pack_size - entry->in_pack_offset;
                unsigned long size, used;
                unsigned char *buf;
                struct object_entry *base_entry = NULL;
 
-               use_packed_git(p);
-               buf = p->pack_base;
-               buf += entry->in_pack_offset;
+               buf = use_pack(p, &w_curs, entry->in_pack_offset, NULL);
 
                /* We want in_pack_type even if we do not reuse delta.
                 * There is no point not reusing non-delta representations.
                 */
                used = unpack_object_header_gently(buf, left,
                                                   &entry->in_pack_type, &size);
-               if (!used || left - used <= 20)
-                       die("corrupt pack for %s", sha1_to_hex(entry->sha1));
 
                /* Check if it is delta, and the base is also an object
                 * we are going to pack.  If so we will reuse the existing
@@ -961,21 +1003,26 @@ static void check_object(struct object_entry *entry)
                if (!no_reuse_delta) {
                        unsigned char c, *base_name;
                        unsigned long ofs;
+                       unsigned long used_0;
                        /* there is at least 20 bytes left in the pack */
                        switch (entry->in_pack_type) {
                        case OBJ_REF_DELTA:
-                               base_name = buf + used;
+                               base_name = use_pack(p, &w_curs,
+                                       entry->in_pack_offset + used, NULL);
                                used += 20;
                                break;
                        case OBJ_OFS_DELTA:
-                               c = buf[used++];
+                               buf = use_pack(p, &w_curs,
+                                       entry->in_pack_offset + used, NULL);
+                               used_0 = 0;
+                               c = buf[used_0++];
                                ofs = c & 127;
                                while (c & 128) {
                                        ofs += 1;
                                        if (!ofs || ofs & ~(~0UL >> 7))
                                                die("delta base offset overflow in pack for %s",
                                                    sha1_to_hex(entry->sha1));
-                                       c = buf[used++];
+                                       c = buf[used_0++];
                                        ofs = (ofs << 7) + (c & 127);
                                }
                                if (ofs >= entry->in_pack_offset)
@@ -983,6 +1030,7 @@ static void check_object(struct object_entry *entry)
                                            sha1_to_hex(entry->sha1));
                                ofs = entry->in_pack_offset - ofs;
                                base_name = find_packed_object_name(p, ofs);
+                               used += used_0;
                                break;
                        default:
                                base_name = NULL;
@@ -990,7 +1038,7 @@ static void check_object(struct object_entry *entry)
                        if (base_name)
                                base_entry = locate_object_entry(base_name);
                }
-               unuse_packed_git(p);
+               unuse_pack(&w_curs);
                entry->in_pack_header_size = used;
 
                if (base_entry) {
index 7d39d9bcd178a65686d6757f8a89065d25f55b23..4e31c273f48e3983aaf99dc6525982d34b6fed06 100644 (file)
@@ -55,6 +55,7 @@ int cmd_verify_pack(int argc, const char **argv, const char *prefix)
        int no_more_options = 0;
        int nothing_done = 1;
 
+       git_config(git_default_config);
        while (1 < argc) {
                if (!no_more_options && argv[1][0] == '-') {
                        if (!strcmp("-v", argv[1]))
diff --git a/cache.h b/cache.h
index 31b0819e83d7f76ed52db7771cf274e74b2156dc..36be64e3868456b11bc9a6024be5e955074241b2 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -197,6 +197,8 @@ extern int warn_ambiguous_refs;
 extern int shared_repository;
 extern const char *apply_default_whitespace;
 extern int zlib_compression_level;
+extern size_t packed_git_window_size;
+extern size_t packed_git_limit;
 
 #define GIT_REPO_VERSION 0
 extern int repository_format_version;
@@ -336,14 +338,22 @@ extern struct alternate_object_database {
 } *alt_odb_list;
 extern void prepare_alt_odb(void);
 
+struct pack_window {
+       struct pack_window *next;
+       unsigned char *base;
+       off_t offset;
+       size_t len;
+       unsigned int last_used;
+       unsigned int inuse_cnt;
+};
+
 extern struct packed_git {
        struct packed_git *next;
-       unsigned long index_size;
-       unsigned long pack_size;
+       struct pack_window *windows;
        unsigned int *index_base;
-       void *pack_base;
-       unsigned int pack_last_used;
-       unsigned int pack_use_cnt;
+       off_t index_size;
+       off_t pack_size;
+       int pack_fd;
        int pack_local;
        unsigned char sha1[20];
        /* something like ".git/objects/pack/xxxxx.pack" */
@@ -389,13 +399,14 @@ extern void install_packed_git(struct packed_git *pack);
 extern struct packed_git *find_sha1_pack(const unsigned char *sha1, 
                                         struct packed_git *packs);
 
-extern int use_packed_git(struct packed_git *);
-extern void unuse_packed_git(struct packed_git *);
+extern void pack_report();
+extern unsigned char* use_pack(struct packed_git *, struct pack_window **, unsigned long, unsigned int *);
+extern void unuse_pack(struct pack_window **);
 extern struct packed_git *add_packed_git(char *, int, int);
 extern int num_packed_objects(const struct packed_git *p);
 extern int nth_packed_object_sha1(const struct packed_git *, int, unsigned char*);
 extern unsigned long find_pack_entry_one(const unsigned char *, struct packed_git *);
-extern void *unpack_entry_gently(struct packed_git *, unsigned long, char *, unsigned long *);
+extern void *unpack_entry(struct packed_git *, unsigned long, char *, unsigned long *);
 extern unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep);
 extern void packed_object_info_detail(struct packed_git *, unsigned long, char *, unsigned long *, unsigned long *, unsigned int *, unsigned char *);
 
@@ -421,6 +432,7 @@ extern char *git_commit_encoding;
 extern char *git_log_output_encoding;
 
 extern int copy_fd(int ifd, int ofd);
+extern void read_or_die(int fd, void *buf, size_t count);
 extern int write_in_full(int fd, const void *buf, size_t count, const char *);
 extern void write_or_die(int fd, const void *buf, size_t count);
 extern int write_or_whine(int fd, const void *buf, size_t count, const char *msg);
index 458ae512f3b644979ddc1f6bb581fee2907dbc2f..5cbd130be2664258b488d8b4ca914550e10906a0 100644 (file)
--- a/config.c
+++ b/config.c
@@ -304,6 +304,21 @@ int git_default_config(const char *var, const char *value)
                return 0;
        }
 
+       if (!strcmp(var, "core.packedgitwindowsize")) {
+               int pgsz = getpagesize();
+               packed_git_window_size = git_config_int(var, value);
+               packed_git_window_size /= pgsz;
+               if (packed_git_window_size < 2)
+                       packed_git_window_size = 2;
+               packed_git_window_size *= pgsz;
+               return 0;
+       }
+
+       if (!strcmp(var, "core.packedgitlimit")) {
+               packed_git_limit = git_config_int(var, value);
+               return 0;
+       }
+
        if (!strcmp(var, "user.name")) {
                strlcpy(git_default_name, value, sizeof(git_default_name));
                return 0;
@@ -695,7 +710,7 @@ int git_config_set_multivar(const char* key, const char* value,
                }
 
                fstat(in_fd, &st);
-               contents = mmap(NULL, st.st_size, PROT_READ,
+               contents = xmmap(NULL, st.st_size, PROT_READ,
                        MAP_PRIVATE, in_fd, 0);
                close(in_fd);
 
diff --git a/diff.c b/diff.c
index 2c2e9dcb8c83709df37d6d57bdfe13bb0e85c0ba..e1b016f47f8eb37a89bdb6cb98435bad7d9dc111 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -1341,10 +1341,8 @@ int diff_populate_filespec(struct diff_filespec *s, int size_only)
                fd = open(s->path, O_RDONLY);
                if (fd < 0)
                        goto err_empty;
-               s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
+               s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
                close(fd);
-               if (s->data == MAP_FAILED)
-                       goto err_empty;
                s->should_munmap = 1;
        }
        else {
index a1502c4e87c0067c8cc276006317005a0da21a49..09976c7bf63a2a1f77854f8157d430c00c0e3473 100644 (file)
@@ -23,6 +23,8 @@ char *git_log_output_encoding;
 int shared_repository = PERM_UMASK;
 const char *apply_default_whitespace;
 int zlib_compression_level = Z_DEFAULT_COMPRESSION;
+size_t packed_git_window_size = DEFAULT_PACKED_GIT_WINDOW_SIZE;
+size_t packed_git_limit = DEFAULT_PACKED_GIT_LIMIT;
 int pager_in_use;
 int pager_use_color = 1;
 
index 5d9eb2615b2e21979f547199121828aafbf02135..e023bf141363d87abfef358134e484ea85f32a15 100644 (file)
@@ -92,12 +92,21 @@ extern void set_warn_routine(void (*routine)(const char *warn, va_list params));
 extern void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset);
 extern int git_munmap(void *start, size_t length);
 
+#define DEFAULT_PACKED_GIT_WINDOW_SIZE (1 * 1024 * 1024)
+
 #else /* NO_MMAP */
 
 #include <sys/mman.h>
+#define DEFAULT_PACKED_GIT_WINDOW_SIZE \
+       (sizeof(void*) >= 8 \
+               ?  1 * 1024 * 1024 * 1024 \
+               : 32 * 1024 * 1024)
 
 #endif /* NO_MMAP */
 
+#define DEFAULT_PACKED_GIT_LIMIT \
+       ((1024L * 1024L) * (sizeof(void*) >= 8 ? 8192 : 256))
+
 #ifdef NO_SETENV
 #define setenv gitsetenv
 extern int gitsetenv(const char *, const char *, int);
@@ -118,11 +127,17 @@ extern char *gitstrcasestr(const char *haystack, const char *needle);
 extern size_t gitstrlcpy(char *, const char *, size_t);
 #endif
 
+extern void release_pack_memory(size_t);
+
 static inline char* xstrdup(const char *str)
 {
        char *ret = strdup(str);
-       if (!ret)
-               die("Out of memory, strdup failed");
+       if (!ret) {
+               release_pack_memory(strlen(str) + 1);
+               ret = strdup(str);
+               if (!ret)
+                       die("Out of memory, strdup failed");
+       }
        return ret;
 }
 
@@ -131,8 +146,14 @@ static inline void *xmalloc(size_t size)
        void *ret = malloc(size);
        if (!ret && !size)
                ret = malloc(1);
-       if (!ret)
-               die("Out of memory, malloc failed");
+       if (!ret) {
+               release_pack_memory(size);
+               ret = malloc(size);
+               if (!ret && !size)
+                       ret = malloc(1);
+               if (!ret)
+                       die("Out of memory, malloc failed");
+       }
 #ifdef XMALLOC_POISON
        memset(ret, 0xA5, size);
 #endif
@@ -144,8 +165,14 @@ static inline void *xrealloc(void *ptr, size_t size)
        void *ret = realloc(ptr, size);
        if (!ret && !size)
                ret = realloc(ptr, 1);
-       if (!ret)
-               die("Out of memory, realloc failed");
+       if (!ret) {
+               release_pack_memory(size);
+               ret = realloc(ptr, size);
+               if (!ret && !size)
+                       ret = realloc(ptr, 1);
+               if (!ret)
+                       die("Out of memory, realloc failed");
+       }
        return ret;
 }
 
@@ -154,8 +181,27 @@ static inline void *xcalloc(size_t nmemb, size_t size)
        void *ret = calloc(nmemb, size);
        if (!ret && (!nmemb || !size))
                ret = calloc(1, 1);
-       if (!ret)
-               die("Out of memory, calloc failed");
+       if (!ret) {
+               release_pack_memory(nmemb * size);
+               ret = calloc(nmemb, size);
+               if (!ret && (!nmemb || !size))
+                       ret = calloc(1, 1);
+               if (!ret)
+                       die("Out of memory, calloc failed");
+       }
+       return ret;
+}
+
+static inline void *xmmap(void *start, size_t length,
+       int prot, int flags, int fd, off_t offset)
+{
+       void *ret = mmap(start, length, prot, flags, fd, offset);
+       if (ret == MAP_FAILED) {
+               release_pack_memory(length);
+               ret = mmap(start, length, prot, flags, fd, offset);
+               if (ret == MAP_FAILED)
+                       die("Out of memory? mmap failed: %s", strerror(errno));
+       }
        return ret;
 }
 
index 8e123b71ed7898d2054ed9ef729c70ed40422bc3..08a9fd8dc09056c1b21cb7414f2467cffcdef077 100644 (file)
@@ -1,55 +1,45 @@
 #include "cache.h"
 #include "pack.h"
 
-#define BATCH (1u<<20)
-
-static int verify_packfile(struct packed_git *p)
+static int verify_packfile(struct packed_git *p,
+               struct pack_window **w_curs)
 {
        unsigned long index_size = p->index_size;
        void *index_base = p->index_base;
        SHA_CTX ctx;
        unsigned char sha1[20];
-       struct pack_header *hdr;
+       unsigned long offset = 0, pack_sig = p->pack_size - 20;
        int nr_objects, err, i;
-       unsigned char *packdata;
-       unsigned long datasize;
-
-       /* Header consistency check */
-       hdr = p->pack_base;
-       if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
-               return error("Packfile %s signature mismatch", p->pack_name);
-       if (!pack_version_ok(hdr->hdr_version))
-               return error("Packfile version %d unsupported",
-                            ntohl(hdr->hdr_version));
-       nr_objects = ntohl(hdr->hdr_entries);
-       if (num_packed_objects(p) != nr_objects)
-               return error("Packfile claims to have %d objects, "
-                            "while idx size expects %d", nr_objects,
-                            num_packed_objects(p));
-
-       /* Check integrity of pack data with its SHA-1 checksum */
+
+       /* Note that the pack header checks are actually performed by
+        * use_pack when it first opens the pack file.  If anything
+        * goes wrong during those checks then the call will die out
+        * immediately.
+        */
+
        SHA1_Init(&ctx);
-       packdata = p->pack_base;
-       datasize = p->pack_size - 20;
-       while (datasize) {
-               unsigned long batch = (datasize < BATCH) ? datasize : BATCH;
-               SHA1_Update(&ctx, packdata, batch);
-               datasize -= batch;
-               packdata += batch;
+       while (offset < pack_sig) {
+               unsigned int remaining;
+               unsigned char *in = use_pack(p, w_curs, offset, &remaining);
+               offset += remaining;
+               if (offset > pack_sig)
+                       remaining -= offset - pack_sig;
+               SHA1_Update(&ctx, in, remaining);
        }
        SHA1_Final(sha1, &ctx);
-
-       if (hashcmp(sha1, (unsigned char *)(p->pack_base) + p->pack_size - 20))
+       if (hashcmp(sha1, use_pack(p, w_curs, pack_sig, NULL)))
                return error("Packfile %s SHA1 mismatch with itself",
                             p->pack_name);
        if (hashcmp(sha1, (unsigned char *)index_base + index_size - 40))
                return error("Packfile %s SHA1 mismatch with idx",
                             p->pack_name);
+       unuse_pack(w_curs);
 
        /* Make sure everything reachable from idx is valid.  Since we
         * have verified that nr_objects matches between idx and pack,
         * we do not do scan-streaming check on the pack file.
         */
+       nr_objects = num_packed_objects(p);
        for (i = err = 0; i < nr_objects; i++) {
                unsigned char sha1[20];
                void *data;
@@ -61,7 +51,7 @@ static int verify_packfile(struct packed_git *p)
                offset = find_pack_entry_one(sha1, p);
                if (!offset)
                        die("internal error pack-check find-pack-entry-one");
-               data = unpack_entry_gently(p, offset, type, &size);
+               data = unpack_entry(p, offset, type, &size);
                if (!data) {
                        err = error("cannot unpack %s from %s",
                                    sha1_to_hex(sha1), p->pack_name);
@@ -84,12 +74,10 @@ static int verify_packfile(struct packed_git *p)
 
 static void show_pack_info(struct packed_git *p)
 {
-       struct pack_header *hdr;
        int nr_objects, i;
        unsigned int chain_histogram[MAX_CHAIN];
 
-       hdr = p->pack_base;
-       nr_objects = ntohl(hdr->hdr_entries);
+       nr_objects = num_packed_objects(p);
        memset(chain_histogram, 0, sizeof(chain_histogram));
 
        for (i = 0; i < nr_objects; i++) {
@@ -152,18 +140,16 @@ int verify_pack(struct packed_git *p, int verbose)
 
        if (!ret) {
                /* Verify pack file */
-               use_packed_git(p);
-               ret = verify_packfile(p);
-               unuse_packed_git(p);
+               struct pack_window *w_curs = NULL;
+               ret = verify_packfile(p, &w_curs);
+               unuse_pack(&w_curs);
        }
 
        if (verbose) {
                if (ret)
                        printf("%s: bad\n", p->pack_name);
                else {
-                       use_packed_git(p);
                        show_pack_info(p);
-                       unuse_packed_git(p);
                        printf("%s: ok\n", p->pack_name);
                }
        }
index b8d83ccd9f7985d60f69b7cd44db698d4e932612..29cf9abe6455313d94d169cc5f16aac21cad3228 100644 (file)
@@ -793,16 +793,16 @@ int read_cache_from(const char *path)
                die("index file open failed (%s)", strerror(errno));
        }
 
-       cache_mmap = MAP_FAILED;
        if (!fstat(fd, &st)) {
                cache_mmap_size = st.st_size;
                errno = EINVAL;
                if (cache_mmap_size >= sizeof(struct cache_header) + 20)
-                       cache_mmap = mmap(NULL, cache_mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
-       }
+                       cache_mmap = xmmap(NULL, cache_mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
+               else
+                       die("index file smaller than expected");
+       } else
+               die("cannot stat the open index (%s)", strerror(errno));
        close(fd);
-       if (cache_mmap == MAP_FAILED)
-               die("index file mmap failed (%s)", strerror(errno));
 
        hdr = cache_mmap;
        if (verify_hdr(hdr, cache_mmap_size) < 0)
diff --git a/refs.c b/refs.c
index f76b4fe20dea81f99b330103ce9d05cc6364c96c..52057455a20cb4641005c9248b5499cca83c77c1 100644 (file)
--- a/refs.c
+++ b/refs.c
@@ -1025,7 +1025,7 @@ int read_ref_at(const char *ref, unsigned long at_time, int cnt, unsigned char *
        fstat(logfd, &st);
        if (!st.st_size)
                die("Log %s is empty.", logfile);
-       logdata = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, logfd, 0);
+       logdata = xmmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, logfd, 0);
        close(logfd);
 
        lastrec = NULL;
index 1c4df5b73e9dff900c69c0994eb21105614511b6..d9622d95e7e3d7b91982ae60dbc36a7996856682 100644 (file)
@@ -355,10 +355,8 @@ static void read_info_alternates(const char * relative_base, int depth)
                close(fd);
                return;
        }
-       map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+       map = xmmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
        close(fd);
-       if (map == MAP_FAILED)
-               return;
 
        link_alt_odb_entries(map, map + st.st_size, '\n', relative_base, depth);
 
@@ -397,11 +395,35 @@ static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
        return NULL;
 }
 
-#define PACK_MAX_SZ (1<<26)
-static int pack_used_ctr;
-static unsigned long pack_mapped;
+static unsigned int pack_used_ctr;
+static unsigned int pack_mmap_calls;
+static unsigned int peak_pack_open_windows;
+static unsigned int pack_open_windows;
+static size_t peak_pack_mapped;
+static size_t pack_mapped;
+static size_t page_size;
 struct packed_git *packed_git;
 
+void pack_report()
+{
+       fprintf(stderr,
+               "pack_report: getpagesize()            = %10lu\n"
+               "pack_report: core.packedGitWindowSize = %10lu\n"
+               "pack_report: core.packedGitLimit      = %10lu\n",
+               page_size,
+               packed_git_window_size,
+               packed_git_limit);
+       fprintf(stderr,
+               "pack_report: pack_used_ctr            = %10u\n"
+               "pack_report: pack_mmap_calls          = %10u\n"
+               "pack_report: pack_open_windows        = %10u / %10u\n"
+               "pack_report: pack_mapped              = %10lu / %10lu\n",
+               pack_used_ctr,
+               pack_mmap_calls,
+               pack_open_windows, peak_pack_open_windows,
+               pack_mapped, peak_pack_mapped);
+}
+
 static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
                                void **idx_map_)
 {
@@ -418,10 +440,8 @@ static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
                return -1;
        }
        idx_size = st.st_size;
-       idx_map = mmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
+       idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
        close(fd);
-       if (idx_map == MAP_FAILED)
-               return -1;
 
        index = idx_map;
        *idx_map_ = idx_map;
@@ -451,86 +471,198 @@ static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
        return 0;
 }
 
-static int unuse_one_packed_git(void)
+static void scan_windows(struct packed_git *p,
+       struct packed_git **lru_p,
+       struct pack_window **lru_w,
+       struct pack_window **lru_l)
 {
-       struct packed_git *p, *lru = NULL;
+       struct pack_window *w, *w_l;
 
-       for (p = packed_git; p; p = p->next) {
-               if (p->pack_use_cnt || !p->pack_base)
-                       continue;
-               if (!lru || p->pack_last_used < lru->pack_last_used)
-                       lru = p;
+       for (w_l = NULL, w = p->windows; w; w = w->next) {
+               if (!w->inuse_cnt) {
+                       if (!*lru_w || w->last_used < (*lru_w)->last_used) {
+                               *lru_p = p;
+                               *lru_w = w;
+                               *lru_l = w_l;
+                       }
+               }
+               w_l = w;
        }
-       if (!lru)
-               return 0;
-       munmap(lru->pack_base, lru->pack_size);
-       lru->pack_base = NULL;
-       return 1;
 }
 
-void unuse_packed_git(struct packed_git *p)
+static int unuse_one_window(struct packed_git *current)
+{
+       struct packed_git *p, *lru_p = NULL;
+       struct pack_window *lru_w = NULL, *lru_l = NULL;
+
+       if (current)
+               scan_windows(current, &lru_p, &lru_w, &lru_l);
+       for (p = packed_git; p; p = p->next)
+               scan_windows(p, &lru_p, &lru_w, &lru_l);
+       if (lru_p) {
+               munmap(lru_w->base, lru_w->len);
+               pack_mapped -= lru_w->len;
+               if (lru_l)
+                       lru_l->next = lru_w->next;
+               else {
+                       lru_p->windows = lru_w->next;
+                       if (!lru_p->windows && lru_p != current) {
+                               close(lru_p->pack_fd);
+                               lru_p->pack_fd = -1;
+                       }
+               }
+               free(lru_w);
+               pack_open_windows--;
+               return 1;
+       }
+       return 0;
+}
+
+void release_pack_memory(size_t need)
 {
-       p->pack_use_cnt--;
+       size_t cur = pack_mapped;
+       while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
+               ; /* nothing */
 }
 
-int use_packed_git(struct packed_git *p)
+void unuse_pack(struct pack_window **w_cursor)
 {
+       struct pack_window *w = *w_cursor;
+       if (w) {
+               w->inuse_cnt--;
+               *w_cursor = NULL;
+       }
+}
+
+static void open_packed_git(struct packed_git *p)
+{
+       struct stat st;
+       struct pack_header hdr;
+       unsigned char sha1[20];
+       unsigned char *idx_sha1;
+       long fd_flag;
+
+       p->pack_fd = open(p->pack_name, O_RDONLY);
+       if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
+               die("packfile %s cannot be opened", p->pack_name);
+
+       /* If we created the struct before we had the pack we lack size. */
        if (!p->pack_size) {
-               struct stat st;
-               /* We created the struct before we had the pack */
-               stat(p->pack_name, &st);
                if (!S_ISREG(st.st_mode))
                        die("packfile %s not a regular file", p->pack_name);
                p->pack_size = st.st_size;
-       }
-       if (!p->pack_base) {
-               int fd;
-               struct stat st;
-               void *map;
-               struct pack_header *hdr;
-
-               pack_mapped += p->pack_size;
-               while (PACK_MAX_SZ < pack_mapped && unuse_one_packed_git())
-                       ; /* nothing */
-               fd = open(p->pack_name, O_RDONLY);
-               if (fd < 0)
-                       die("packfile %s cannot be opened", p->pack_name);
-               if (fstat(fd, &st)) {
-                       close(fd);
-                       die("packfile %s cannot be opened", p->pack_name);
-               }
-               if (st.st_size != p->pack_size)
-                       die("packfile %s size mismatch.", p->pack_name);
-               map = mmap(NULL, p->pack_size, PROT_READ, MAP_PRIVATE, fd, 0);
-               close(fd);
-               if (map == MAP_FAILED)
-                       die("packfile %s cannot be mapped.", p->pack_name);
-               p->pack_base = map;
+       } else if (p->pack_size != st.st_size)
+               die("packfile %s size changed", p->pack_name);
 
-               /* Check if we understand this pack file.  If we don't we're
-                * likely too old to handle it.
-                */
-               hdr = map;
-               if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
-                       die("packfile %s isn't actually a pack.", p->pack_name);
-               if (!pack_version_ok(hdr->hdr_version))
-                       die("packfile %s is version %i and not supported"
-                               " (try upgrading GIT to a newer version)",
-                               p->pack_name, ntohl(hdr->hdr_version));
-
-               /* Check if the pack file matches with the index file.
-                * this is cheap.
-                */
-               if (hashcmp((unsigned char *)(p->index_base) +
-                           p->index_size - 40,
-                           (unsigned char *)p->pack_base +
-                           p->pack_size - 20)) {
-                       die("packfile %s does not match index.", p->pack_name);
+       /* We leave these file descriptors open with sliding mmap;
+        * there is no point keeping them open across exec(), though.
+        */
+       fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
+       if (fd_flag < 0)
+               die("cannot determine file descriptor flags");
+       fd_flag |= FD_CLOEXEC;
+       if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
+               die("cannot set FD_CLOEXEC");
+
+       /* Verify we recognize this pack file format. */
+       read_or_die(p->pack_fd, &hdr, sizeof(hdr));
+       if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
+               die("file %s is not a GIT packfile", p->pack_name);
+       if (!pack_version_ok(hdr.hdr_version))
+               die("packfile %s is version %u and not supported"
+                       " (try upgrading GIT to a newer version)",
+                       p->pack_name, ntohl(hdr.hdr_version));
+
+       /* Verify the pack matches its index. */
+       if (num_packed_objects(p) != ntohl(hdr.hdr_entries))
+               die("packfile %s claims to have %u objects"
+                       " while index size indicates %u objects",
+                       p->pack_name, ntohl(hdr.hdr_entries),
+                       num_packed_objects(p));
+       if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
+               die("end of packfile %s is unavailable", p->pack_name);
+       read_or_die(p->pack_fd, sha1, sizeof(sha1));
+       idx_sha1 = ((unsigned char *)p->index_base) + p->index_size - 40;
+       if (hashcmp(sha1, idx_sha1))
+               die("packfile %s does not match index", p->pack_name);
+}
+
+static int in_window(struct pack_window *win, unsigned long offset)
+{
+       /* We must promise at least 20 bytes (one hash) after the
+        * offset is available from this window, otherwise the offset
+        * is not actually in this window and a different window (which
+        * has that one hash excess) must be used.  This is to support
+        * the object header and delta base parsing routines below.
+        */
+       off_t win_off = win->offset;
+       return win_off <= offset
+               && (offset + 20) <= (win_off + win->len);
+}
+
+unsigned char* use_pack(struct packed_git *p,
+               struct pack_window **w_cursor,
+               unsigned long offset,
+               unsigned int *left)
+{
+       struct pack_window *win = *w_cursor;
+
+       if (p->pack_fd == -1)
+               open_packed_git(p);
+
+       /* Since packfiles end in a hash of their content and its
+        * pointless to ask for an offset into the middle of that
+        * hash, and the in_window function above wouldn't match
+        * don't allow an offset too close to the end of the file.
+        */
+       if (offset > (p->pack_size - 20))
+               die("offset beyond end of packfile (truncated pack?)");
+
+       if (!win || !in_window(win, offset)) {
+               if (win)
+                       win->inuse_cnt--;
+               for (win = p->windows; win; win = win->next) {
+                       if (in_window(win, offset))
+                               break;
+               }
+               if (!win) {
+                       if (!page_size)
+                               page_size = getpagesize();
+                       win = xcalloc(1, sizeof(*win));
+                       win->offset = (offset / page_size) * page_size;
+                       win->len = p->pack_size - win->offset;
+                       if (win->len > packed_git_window_size)
+                               win->len = packed_git_window_size;
+                       pack_mapped += win->len;
+                       while (packed_git_limit < pack_mapped
+                               && unuse_one_window(p))
+                               ; /* nothing */
+                       win->base = xmmap(NULL, win->len,
+                               PROT_READ, MAP_PRIVATE,
+                               p->pack_fd, win->offset);
+                       if (win->base == MAP_FAILED)
+                               die("packfile %s cannot be mapped: %s",
+                                       p->pack_name,
+                                       strerror(errno));
+                       pack_mmap_calls++;
+                       pack_open_windows++;
+                       if (pack_mapped > peak_pack_mapped)
+                               peak_pack_mapped = pack_mapped;
+                       if (pack_open_windows > peak_pack_open_windows)
+                               peak_pack_open_windows = pack_open_windows;
+                       win->next = p->windows;
+                       p->windows = win;
                }
        }
-       p->pack_last_used = pack_used_ctr++;
-       p->pack_use_cnt++;
-       return 0;
+       if (win != *w_cursor) {
+               win->last_used = pack_used_ctr++;
+               win->inuse_cnt++;
+               *w_cursor = win;
+       }
+       offset -= win->offset;
+       if (left)
+               *left = win->len - offset;
+       return win->base + offset;
 }
 
 struct packed_git *add_packed_git(char *path, int path_len, int local)
@@ -559,9 +691,8 @@ struct packed_git *add_packed_git(char *path, int path_len, int local)
        p->pack_size = st.st_size;
        p->index_base = idx_map;
        p->next = NULL;
-       p->pack_base = NULL;
-       p->pack_last_used = 0;
-       p->pack_use_cnt = 0;
+       p->windows = NULL;
+       p->pack_fd = -1;
        p->pack_local = local;
        if ((path_len > 44) && !get_sha1_hex(path + path_len - 44, sha1))
                hashcpy(p->sha1, sha1);
@@ -592,9 +723,8 @@ struct packed_git *parse_pack_index_file(const unsigned char *sha1, char *idx_pa
        p->pack_size = 0;
        p->index_base = idx_map;
        p->next = NULL;
-       p->pack_base = NULL;
-       p->pack_last_used = 0;
-       p->pack_use_cnt = 0;
+       p->windows = NULL;
+       p->pack_fd = -1;
        hashcpy(p->sha1, sha1);
        return p;
 }
@@ -705,10 +835,8 @@ void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
                 */
                sha1_file_open_flag = 0;
        }
-       map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+       map = xmmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
        close(fd);
-       if (map == MAP_FAILED)
-               return NULL;
        *size = st.st_size;
        return map;
 }
@@ -878,18 +1006,21 @@ void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned l
 }
 
 static unsigned long get_delta_base(struct packed_git *p,
+                                   struct pack_window **w_curs,
                                    unsigned long offset,
                                    enum object_type kind,
                                    unsigned long delta_obj_offset,
                                    unsigned long *base_obj_offset)
 {
-       unsigned char *base_info = (unsigned char *) p->pack_base + offset;
+       unsigned char *base_info = use_pack(p, w_curs, offset, NULL);
        unsigned long base_offset;
 
-       /* there must be at least 20 bytes left regardless of delta type */
-       if (p->pack_size <= offset + 20)
-               die("truncated pack file");
-
+       /* use_pack() assured us we have [base_info, base_info + 20)
+        * as a range that we can look at without walking off the
+        * end of the mapped window.  Its actually the hash size
+        * that is assured.  An OFS_DELTA longer than the hash size
+        * is stupid, as then a REF_DELTA would be smaller to store.
+        */
        if (kind == OBJ_OFS_DELTA) {
                unsigned used = 0;
                unsigned char c = base_info[used++];
@@ -923,6 +1054,7 @@ static int packed_object_info(struct packed_git *p, unsigned long offset,
                              char *type, unsigned long *sizep);
 
 static int packed_delta_info(struct packed_git *p,
+                            struct pack_window **w_curs,
                             unsigned long offset,
                             enum object_type kind,
                             unsigned long obj_offset,
@@ -931,7 +1063,8 @@ static int packed_delta_info(struct packed_git *p,
 {
        unsigned long base_offset;
 
-       offset = get_delta_base(p, offset, kind, obj_offset, &base_offset);
+       offset = get_delta_base(p, w_curs, offset, kind,
+               obj_offset, &base_offset);
 
        /* We choose to only get the type of the base object and
         * ignore potentially corrupt pack file that expects the delta
@@ -943,20 +1076,23 @@ static int packed_delta_info(struct packed_git *p,
 
        if (sizep) {
                const unsigned char *data;
-               unsigned char delta_head[20];
+               unsigned char delta_head[20], *in;
                unsigned long result_size;
                z_stream stream;
                int st;
 
                memset(&stream, 0, sizeof(stream));
-
-               stream.next_in = (unsigned char *) p->pack_base + offset;
-               stream.avail_in = p->pack_size - offset;
                stream.next_out = delta_head;
                stream.avail_out = sizeof(delta_head);
 
                inflateInit(&stream);
-               st = inflate(&stream, Z_FINISH);
+               do {
+                       in = use_pack(p, w_curs, offset, &stream.avail_in);
+                       stream.next_in = in;
+                       st = inflate(&stream, Z_FINISH);
+                       offset += 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))
@@ -977,17 +1113,24 @@ static int packed_delta_info(struct packed_git *p,
        return 0;
 }
 
-static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
-       enum object_type *type, unsigned long *sizep)
+static unsigned long unpack_object_header(struct packed_git *p,
+               struct pack_window **w_curs,
+               unsigned long offset,
+               enum object_type *type,
+               unsigned long *sizep)
 {
+       unsigned char *base;
+       unsigned int left;
        unsigned long used;
 
-       if (p->pack_size <= offset)
-               die("object offset outside of pack file");
-
-       used = unpack_object_header_gently((unsigned char *)p->pack_base +
-                                          offset,
-                                          p->pack_size - offset, type, sizep);
+       /* use_pack() assures us we have [base, base + 20) available
+        * as a range that we can look at at.  (Its actually the hash
+        * size that is assurred.)  With our object header encoding
+        * the maximum deflated object size is 2^137, which is just
+        * insane, so we know won't exceed what we have been given.
+        */
+       base = use_pack(p, w_curs, offset, &left);
+       used = unpack_object_header_gently(base, left, type, sizep);
        if (!used)
                die("object offset outside of pack file");
 
@@ -1002,13 +1145,14 @@ void packed_object_info_detail(struct packed_git *p,
                               unsigned int *delta_chain_length,
                               unsigned char *base_sha1)
 {
+       struct pack_window *w_curs = NULL;
        unsigned long obj_offset, val;
        unsigned char *next_sha1;
        enum object_type kind;
 
        *delta_chain_length = 0;
        obj_offset = offset;
-       offset = unpack_object_header(p, offset, &kind, size);
+       offset = unpack_object_header(p, &w_curs, offset, &kind, size);
 
        for (;;) {
                switch (kind) {
@@ -1021,25 +1165,24 @@ void packed_object_info_detail(struct packed_git *p,
                case OBJ_TAG:
                        strcpy(type, type_names[kind]);
                        *store_size = 0; /* notyet */
+                       unuse_pack(&w_curs);
                        return;
                case OBJ_OFS_DELTA:
-                       get_delta_base(p, offset, kind, obj_offset, &offset);
+                       get_delta_base(p, &w_curs, offset, kind,
+                               obj_offset, &offset);
                        if (*delta_chain_length == 0) {
                                /* TODO: find base_sha1 as pointed by offset */
                        }
                        break;
                case OBJ_REF_DELTA:
-                       if (p->pack_size <= offset + 20)
-                               die("pack file %s records an incomplete delta base",
-                                   p->pack_name);
-                       next_sha1 = (unsigned char *) p->pack_base + offset;
+                       next_sha1 = use_pack(p, &w_curs, offset, NULL);
                        if (*delta_chain_length == 0)
                                hashcpy(base_sha1, next_sha1);
                        offset = find_pack_entry_one(next_sha1, p);
                        break;
                }
                obj_offset = offset;
-               offset = unpack_object_header(p, offset, &kind, &val);
+               offset = unpack_object_header(p, &w_curs, offset, &kind, &val);
                (*delta_chain_length)++;
        }
 }
@@ -1047,20 +1190,26 @@ void packed_object_info_detail(struct packed_git *p,
 static int packed_object_info(struct packed_git *p, unsigned long offset,
                              char *type, unsigned long *sizep)
 {
+       struct pack_window *w_curs = NULL;
        unsigned long size, obj_offset = offset;
        enum object_type kind;
+       int r;
 
-       offset = unpack_object_header(p, offset, &kind, &size);
+       offset = unpack_object_header(p, &w_curs, offset, &kind, &size);
 
        switch (kind) {
        case OBJ_OFS_DELTA:
        case OBJ_REF_DELTA:
-               return packed_delta_info(p, offset, kind, obj_offset, type, sizep);
+               r = packed_delta_info(p, &w_curs, offset, kind,
+                       obj_offset, type, sizep);
+               unuse_pack(&w_curs);
+               return r;
        case OBJ_COMMIT:
        case OBJ_TREE:
        case OBJ_BLOB:
        case OBJ_TAG:
                strcpy(type, type_names[kind]);
+               unuse_pack(&w_curs);
                break;
        default:
                die("pack %s contains unknown object type %d",
@@ -1072,23 +1221,27 @@ static int packed_object_info(struct packed_git *p, unsigned long offset,
 }
 
 static void *unpack_compressed_entry(struct packed_git *p,
+                                   struct pack_window **w_curs,
                                    unsigned long offset,
                                    unsigned long size)
 {
        int st;
        z_stream stream;
-       unsigned char *buffer;
+       unsigned char *buffer, *in;
 
        buffer = xmalloc(size + 1);
        buffer[size] = 0;
        memset(&stream, 0, sizeof(stream));
-       stream.next_in = (unsigned char*)p->pack_base + offset;
-       stream.avail_in = p->pack_size - offset;
        stream.next_out = buffer;
        stream.avail_out = size;
 
        inflateInit(&stream);
-       st = inflate(&stream, Z_FINISH);
+       do {
+               in = use_pack(p, w_curs, offset, &stream.avail_in);
+               stream.next_in = in;
+               st = inflate(&stream, Z_FINISH);
+               offset += stream.next_in - in;
+       } while (st == Z_OK || st == Z_BUF_ERROR);
        inflateEnd(&stream);
        if ((st != Z_STREAM_END) || stream.total_out != size) {
                free(buffer);
@@ -1099,6 +1252,7 @@ static void *unpack_compressed_entry(struct packed_git *p,
 }
 
 static void *unpack_delta_entry(struct packed_git *p,
+                               struct pack_window **w_curs,
                                unsigned long offset,
                                unsigned long delta_size,
                                enum object_type kind,
@@ -1109,13 +1263,14 @@ static void *unpack_delta_entry(struct packed_git *p,
        void *delta_data, *result, *base;
        unsigned long result_size, base_size, base_offset;
 
-       offset = get_delta_base(p, offset, kind, obj_offset, &base_offset);
-       base = unpack_entry_gently(p, base_offset, type, &base_size);
+       offset = get_delta_base(p, w_curs, offset, kind,
+               obj_offset, &base_offset);
+       base = unpack_entry(p, base_offset, type, &base_size);
        if (!base)
                die("failed to read delta base object at %lu from %s",
                    base_offset, p->pack_name);
 
-       delta_data = unpack_compressed_entry(p, offset, delta_size);
+       delta_data = unpack_compressed_entry(p, w_curs, offset, delta_size);
        result = patch_delta(base, base_size,
                             delta_data, delta_size,
                             &result_size);
@@ -1127,43 +1282,34 @@ static void *unpack_delta_entry(struct packed_git *p,
        return result;
 }
 
-static void *unpack_entry(struct pack_entry *entry,
-                         char *type, unsigned long *sizep)
-{
-       struct packed_git *p = entry->p;
-       void *retval;
-
-       if (use_packed_git(p))
-               die("cannot map packed file");
-       retval = unpack_entry_gently(p, entry->offset, type, sizep);
-       unuse_packed_git(p);
-       if (!retval)
-               die("corrupted pack file %s", p->pack_name);
-       return retval;
-}
-
-/* The caller is responsible for use_packed_git()/unuse_packed_git() pair */
-void *unpack_entry_gently(struct packed_git *p, unsigned long offset,
+void *unpack_entry(struct packed_git *p, unsigned long offset,
                          char *type, unsigned long *sizep)
 {
+       struct pack_window *w_curs = NULL;
        unsigned long size, obj_offset = offset;
        enum object_type kind;
+       void *retval;
 
-       offset = unpack_object_header(p, offset, &kind, &size);
+       offset = unpack_object_header(p, &w_curs, offset, &kind, &size);
        switch (kind) {
        case OBJ_OFS_DELTA:
        case OBJ_REF_DELTA:
-               return unpack_delta_entry(p, offset, size, kind, obj_offset, type, sizep);
+               retval = unpack_delta_entry(p, &w_curs, offset, size,
+                       kind, obj_offset, type, sizep);
+               break;
        case OBJ_COMMIT:
        case OBJ_TREE:
        case OBJ_BLOB:
        case OBJ_TAG:
                strcpy(type, type_names[kind]);
                *sizep = size;
-               return unpack_compressed_entry(p, offset, size);
+               retval = unpack_compressed_entry(p, &w_curs, offset, size);
+               break;
        default:
-               return NULL;
+               die("unknown object type %i in %s", kind, p->pack_name);
        }
+       unuse_pack(&w_curs);
+       return retval;
 }
 
 int num_packed_objects(const struct packed_git *p)
@@ -1289,7 +1435,6 @@ static int sha1_loose_object_info(const unsigned char *sha1, char *type, unsigne
 
 int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
 {
-       int status;
        struct pack_entry e;
 
        if (!find_pack_entry(sha1, &e, NULL)) {
@@ -1297,11 +1442,7 @@ int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep
                if (!find_pack_entry(sha1, &e, NULL))
                        return sha1_loose_object_info(sha1, type, sizep);
        }
-       if (use_packed_git(e.p))
-               die("cannot map packed file");
-       status = packed_object_info(e.p, e.offset, type, sizep);
-       unuse_packed_git(e.p);
-       return status;
+       return packed_object_info(e.p, e.offset, type, sizep);
 }
 
 static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
@@ -1312,7 +1453,7 @@ static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned lo
                error("cannot read sha1_file for %s", sha1_to_hex(sha1));
                return NULL;
        }
-       return unpack_entry(&e, type, size);
+       return unpack_entry(e.p, e.offset, type, size);
 }
 
 void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
@@ -1851,10 +1992,8 @@ int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, con
 
        buf = "";
        if (size)
-               buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
+               buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
        close(fd);
-       if (buf == MAP_FAILED)
-               return -1;
 
        if (!type)
                type = blob_type;
diff --git a/t/t5301-sliding-window.sh b/t/t5301-sliding-window.sh
new file mode 100755 (executable)
index 0000000..5a7232a
--- /dev/null
@@ -0,0 +1,60 @@
+#!/bin/sh
+#
+# Copyright (c) 2006 Shawn Pearce
+#
+
+test_description='mmap sliding window tests'
+. ./test-lib.sh
+
+test_expect_success \
+    'setup' \
+    'rm -f .git/index*
+     for i in a b c
+     do
+         echo $i >$i &&
+         dd if=/dev/urandom bs=32k count=1 >>$i &&
+         git-update-index --add $i || return 1
+     done &&
+     echo d >d && cat c >>d && git-update-index --add d &&
+     tree=`git-write-tree` &&
+     commit1=`git-commit-tree $tree </dev/null` &&
+     git-update-ref HEAD $commit1 &&
+     git-repack -a -d &&
+     test "`git-count-objects`" = "0 objects, 0 kilobytes" &&
+     pack1=`ls .git/objects/pack/*.pack` &&
+     test -f "$pack1"'
+
+test_expect_success \
+    'verify-pack -v, defaults' \
+    'git-verify-pack -v "$pack1"'
+
+test_expect_success \
+    'verify-pack -v, packedGitWindowSize == 1 page' \
+    'git-repo-config core.packedGitWindowSize 512 &&
+     git-verify-pack -v "$pack1"'
+
+test_expect_success \
+    'verify-pack -v, packedGit{WindowSize,Limit} == 1 page' \
+    'git-repo-config core.packedGitWindowSize 512 &&
+     git-repo-config core.packedGitLimit 512 &&
+     git-verify-pack -v "$pack1"'
+
+test_expect_success \
+    'repack -a -d, packedGit{WindowSize,Limit} == 1 page' \
+    'git-repo-config core.packedGitWindowSize 512 &&
+     git-repo-config core.packedGitLimit 512 &&
+     commit2=`git-commit-tree $tree -p $commit1 </dev/null` &&
+     git-update-ref HEAD $commit2 &&
+     git-repack -a -d &&
+     test "`git-count-objects`" = "0 objects, 0 kilobytes" &&
+     pack2=`ls .git/objects/pack/*.pack` &&
+     test -f "$pack2"
+     test "$pack1" \!= "$pack2"'
+
+test_expect_success \
+    'verify-pack -v, defaults' \
+    'git-repo-config --unset core.packedGitWindowSize &&
+     git-repo-config --unset core.packedGitLimit &&
+     git-verify-pack -v "$pack2"'
+
+test_done
index 650f13fc012b14a6aaa62534727d4ef9cdce58bd..6db1d3123d1761dee4850e0a56a9b86b4bf1722a 100644 (file)
@@ -1,5 +1,21 @@
 #include "cache.h"
 
+void read_or_die(int fd, void *buf, size_t count)
+{
+       char *p = buf;
+       ssize_t loaded;
+
+       while (count > 0) {
+               loaded = xread(fd, p, count);
+               if (loaded == 0)
+                       die("unexpected end of file");
+               else if (loaded < 0)
+                       die("read error (%s)", strerror(errno));
+               count -= loaded;
+               p += loaded;
+       }
+}
+
 void write_or_die(int fd, const void *buf, size_t count)
 {
        const char *p = buf;