rebase: one safety net, one bugfix and one optimization.
[gitweb.git] / tar-tree.c
index ea7ea91add54532c38dde9e343efe34d56805341..970c4bb54e148282a89f1249a96deca880bccafd 100644 (file)
@@ -1,10 +1,23 @@
+/*
+ * Copyright (c) 2005 Rene Scharfe
+ */
 #include <time.h>
 #include "cache.h"
 
 #define RECORDSIZE     (512)
 #define BLOCKSIZE      (RECORDSIZE * 20)
 
-static const char *tar_tree_usage = "tar-tree <key> [basedir]";
+#define TYPEFLAG_AUTO          '\0'
+#define TYPEFLAG_REG           '0'
+#define TYPEFLAG_LNK           '2'
+#define TYPEFLAG_DIR           '5'
+#define TYPEFLAG_GLOBAL_HEADER 'g'
+#define TYPEFLAG_EXT_HEADER    'x'
+
+#define EXT_HEADER_PATH                1
+#define EXT_HEADER_LINKPATH    2
+
+static const char tar_tree_usage[] = "git-tar-tree <key> [basedir]";
 
 static char block[BLOCKSIZE];
 static unsigned long offset;
@@ -27,9 +40,9 @@ static void reliable_write(void *buf, unsigned long size)
                                continue;
                        if (errno == EPIPE)
                                exit(0);
-                       die("tar-tree: %s", strerror(errno));
+                       die("git-tar-tree: %s", strerror(errno));
                } else if (!ret) {
-                       die("tar-tree: disk full?");
+                       die("git-tar-tree: disk full?");
                }
                size -= ret;
                buf += ret;
@@ -45,22 +58,28 @@ static void write_if_needed(void)
        }
 }
 
+/* acquire the next record from the buffer; user must call write_if_needed() */
+static char *get_record(void)
+{
+       char *p = block + offset;
+       memset(p, 0, RECORDSIZE);
+       offset += RECORDSIZE;
+       return p;
+}
+
 /*
  * The end of tar archives is marked by 1024 nul bytes and after that
  * follows the rest of the block (if any).
  */
 static void write_trailer(void)
 {
-       memset(block + offset, 0, RECORDSIZE);
-       offset += RECORDSIZE;
+       get_record();
        write_if_needed();
-       memset(block + offset, 0, RECORDSIZE);
-       offset += RECORDSIZE;
+       get_record();
        write_if_needed();
-       if (offset) {
-               memset(block + offset, 0, BLOCKSIZE - offset);
-               reliable_write(block, BLOCKSIZE);
-               offset = 0;
+       while (offset) {
+               get_record();
+               write_if_needed();
        }
 }
 
@@ -113,12 +132,6 @@ static void append_char(char **p, char c)
        *p += 1;
 }
 
-static void append_long(char **p, long n)
-{
-       int len = sprintf(*p, "%ld", n);
-       *p += len;
-}
-
 static void append_path_prefix(char **buffer, struct path_prefix *prefix)
 {
        if (!prefix)
@@ -160,83 +173,140 @@ static unsigned int path_len(int is_dir, const char *basepath,
        return len;
 }
 
-static void write_header(const char *, char, const char *, struct path_prefix *,
-                         const char *, unsigned int, unsigned long);
+static void append_extended_header_prefix(char **p, unsigned int size,
+                                          const char *keyword)
+{
+       int len = sprintf(*p, "%u %s=", size, keyword);
+       *p += len;
+}
+
+static unsigned int extended_header_len(const char *keyword,
+                                        unsigned int valuelen)
+{
+       /* "%u %s=%s\n" */
+       unsigned int len = 1 + 1 + strlen(keyword) + 1 + valuelen + 1;
+       if (len > 9)
+               len++;
+       if (len > 99)
+               len++;
+       return len;
+}
+
+static void append_extended_header(char **p, const char *keyword,
+                                   const char *value, unsigned int len)
+{
+       unsigned int size = extended_header_len(keyword, len);
+       append_extended_header_prefix(p, size, keyword);
+       memcpy(*p, value, len);
+       *p += len;
+       append_char(p, '\n');
+}
+
+static void write_header(const unsigned char *, char, const char *, struct path_prefix *,
+                         const char *, unsigned int, void *, unsigned long);
 
 /* stores a pax extended header directly in the block buffer */
 static void write_extended_header(const char *headerfilename, int is_dir,
-                                  const char *basepath,
+                                  unsigned int flags, const char *basepath,
                                   struct path_prefix *prefix,
-                                  const char *path, unsigned int namelen)
+                                  const char *path, unsigned int namelen,
+                                  void *content, unsigned int contentsize)
 {
-       char *p;
-       unsigned int size = 1 + 6 + namelen + 1;
-       if (size > 9)
-               size++;
-       if (size > 99)
-               size++;
-       if (size > RECORDSIZE)
-               die("tar-tree: extended header too big, wtf?");
-       write_header(NULL, 'x', NULL, NULL, headerfilename, 0100600, size);
-       p = block + offset;
-       memset(p, 0, RECORDSIZE);
-       offset += RECORDSIZE;
-       append_long(&p, size);
-       append_string(&p, " path=");
+       char *buffer, *p;
+       unsigned int pathlen, size, linkpathlen = 0;
+
+       size = pathlen = extended_header_len("path", namelen);
+       if (flags & EXT_HEADER_LINKPATH) {
+               linkpathlen = extended_header_len("linkpath", contentsize);
+               size += linkpathlen;
+       }
+       write_header(NULL, TYPEFLAG_EXT_HEADER, NULL, NULL, headerfilename,
+                    0100600, NULL, size);
+
+       buffer = p = malloc(size);
+       if (!buffer)
+               die("git-tar-tree: %s", strerror(errno));
+       append_extended_header_prefix(&p, pathlen, "path");
        append_path(&p, is_dir, basepath, prefix, path);
        append_char(&p, '\n');
-       write_if_needed();
+       if (flags & EXT_HEADER_LINKPATH)
+               append_extended_header(&p, "linkpath", content, contentsize);
+       write_blocked(buffer, size);
+       free(buffer);
 }
 
-static void write_global_extended_header(const char *sha1)
+static void write_global_extended_header(const unsigned char *sha1)
 {
        char *p;
-       write_header(NULL, 'g', NULL, NULL, "pax_global_header", 0, 52);
-       p = block + offset;
-       memset(p, 0, RECORDSIZE);
-       offset += RECORDSIZE;
-       append_long(&p, 52);    /* 2 + 9 + 40 + 1 */
-       append_string(&p, " comment=");
-       append_string(&p, sha1_to_hex(sha1));
-       append_char(&p, '\n');
+       unsigned int size;
+
+       size = extended_header_len("comment", 40);
+       write_header(NULL, TYPEFLAG_GLOBAL_HEADER, NULL, NULL,
+                    "pax_global_header", 0100600, NULL, size);
+
+       p = get_record();
+       append_extended_header(&p, "comment", sha1_to_hex(sha1), 40);
        write_if_needed();
 }
 
 /* stores a ustar header directly in the block buffer */
-static void write_header(const char *sha1, char typeflag, const char *basepath,
+static void write_header(const unsigned char *sha1, char typeflag, const char *basepath,
                          struct path_prefix *prefix, const char *path,
-                         unsigned int mode, unsigned long size)
+                         unsigned int mode, void *buffer, unsigned long size)
 {
        unsigned int namelen; 
-       char *p, *header = NULL;
+       char *header = NULL;
        unsigned int checksum = 0;
        int i;
+       unsigned int ext_header = 0;
+
+       if (typeflag == TYPEFLAG_AUTO) {
+               if (S_ISDIR(mode))
+                       typeflag = TYPEFLAG_DIR;
+               else if (S_ISLNK(mode))
+                       typeflag = TYPEFLAG_LNK;
+               else
+                       typeflag = TYPEFLAG_REG;
+       }
 
        namelen = path_len(S_ISDIR(mode), basepath, prefix, path);
-       if (namelen > 500) {
-               die("tar-tree: name too log of object %s\n", sha1_to_hex(sha1));
-       } else if (namelen > 100) {
-               char *sha1_hex = sha1_to_hex(sha1);
+       if (namelen > 100)
+               ext_header |= EXT_HEADER_PATH;
+       if (typeflag == TYPEFLAG_LNK && size > 100)
+               ext_header |= EXT_HEADER_LINKPATH;
+
+       /* the extended header must be written before the normal one */
+       if (ext_header) {
                char headerfilename[51];
-               sprintf(headerfilename, "%s.paxheader", sha1_hex);
-               /* the extended header must be written before the normal one */
-               write_extended_header(headerfilename, S_ISDIR(mode), basepath,
-                                     prefix, path, namelen);
-
-               header = block + offset;
-               memset(header, 0, RECORDSIZE);
-               offset += RECORDSIZE;
-               sprintf(header, "%s.data", sha1_hex);
+               sprintf(headerfilename, "%s.paxheader", sha1_to_hex(sha1));
+               write_extended_header(headerfilename, S_ISDIR(mode),
+                                     ext_header, basepath, prefix, path,
+                                     namelen, buffer, size);
+       }
+
+       header = get_record();
+
+       if (ext_header) {
+               sprintf(header, "%s.data", sha1_to_hex(sha1));
        } else {
-               header = block + offset;
-               memset(header, 0, RECORDSIZE);
-               offset += RECORDSIZE;
-               p = header;
+               char *p = header;
                append_path(&p, S_ISDIR(mode), basepath, prefix, path);
        }
 
+       if (typeflag == TYPEFLAG_LNK) {
+               if (ext_header & EXT_HEADER_LINKPATH) {
+                       sprintf(&header[157], "see %s.paxheader",
+                               sha1_to_hex(sha1));
+               } else {
+                       if (buffer)
+                               strncpy(&header[157], buffer, size);
+               }
+       }
+
        if (S_ISDIR(mode))
                mode |= 0755;   /* GIT doesn't store permissions of dirs */
+       if (S_ISLNK(mode))
+               mode |= 0777;   /* ... nor of symlinks */
        sprintf(&header[100], "%07o", mode & 07777);
 
        /* XXX: should we provide more meaningful info here? */
@@ -245,7 +315,9 @@ static void write_header(const char *sha1, char typeflag, const char *basepath,
        strncpy(&header[265], "git", 31);       /* uname */
        strncpy(&header[297], "git", 31);       /* gname */
 
-       sprintf(&header[124], "%011lo", S_ISDIR(mode) ? 0 : size);
+       if (S_ISDIR(mode) || S_ISLNK(mode))
+               size = 0;
+       sprintf(&header[124], "%011lo", size);
        sprintf(&header[136], "%011lo", archive_time);
 
        header[156] = typeflag;
@@ -253,8 +325,8 @@ static void write_header(const char *sha1, char typeflag, const char *basepath,
        memcpy(&header[257], "ustar", 6);
        memcpy(&header[263], "00", 2);
 
-       printf(&header[329], "%07o", 0);        /* devmajor */
-       printf(&header[337], "%07o", 0);        /* devminor */
+       sprintf(&header[329], "%07o", 0);       /* devmajor */
+       sprintf(&header[337], "%07o", 0);       /* devminor */
 
        memset(&header[148], ' ', 8);
        for (i = 0; i < RECORDSIZE; i++)
@@ -281,18 +353,20 @@ static void traverse_tree(void *buffer, unsigned long size,
 
                if (size < namelen + 20 || sscanf(buffer, "%o", &mode) != 1)
                        die("corrupt 'tree' file");
+               if (S_ISDIR(mode) || S_ISREG(mode))
+                       mode |= (mode & 0100) ? 0777 : 0666;
                buffer = sha1 + 20;
                size -= namelen + 20;
 
                eltbuf = read_sha1_file(sha1, elttype, &eltsize);
                if (!eltbuf)
                        die("cannot read %s", sha1_to_hex(sha1));
-               write_header(sha1, S_ISDIR(mode) ? '5' : '0', basedir,
-                            prefix, path, mode, eltsize);
+               write_header(sha1, TYPEFLAG_AUTO, basedir, prefix, path,
+                            mode, eltbuf, eltsize);
                if (!strcmp(elttype, "tree")) {
                        this_prefix.name = path;
                        traverse_tree(eltbuf, eltsize, &this_prefix);
-               } else if (!strcmp(elttype, "blob")) {
+               } else if (!strcmp(elttype, "blob") && !S_ISLNK(mode)) {
                        write_blocked(eltbuf, eltsize);
                }
                free(eltbuf);
@@ -300,7 +374,7 @@ static void traverse_tree(void *buffer, unsigned long size,
 }
 
 /* get commit time from committer line of commit object */
-time_t commit_time(void * buffer, unsigned long size)
+static time_t commit_time(void * buffer, unsigned long size)
 {
        time_t result = 0;
        char *p = buffer;
@@ -338,17 +412,13 @@ int main(int argc, char **argv)
                basedir = argv[2];
                /* FALLTHROUGH */
        case 2:
-               if (get_sha1_hex(argv[1], sha1) < 0)
+               if (get_sha1(argv[1], sha1) < 0)
                        usage(tar_tree_usage);
                break;
        default:
                usage(tar_tree_usage);
        }
 
-       sha1_file_directory = getenv(DB_ENVIRONMENT);
-       if (!sha1_file_directory)
-               sha1_file_directory = DEFAULT_DB_ENVIRONMENT;
-
        buffer = read_object_with_reference(sha1, "commit", &size, commit_sha1);
        if (buffer) {
                write_global_extended_header(commit_sha1);
@@ -362,7 +432,8 @@ int main(int argc, char **argv)
        if (!archive_time)
                archive_time = time(NULL);
        if (basedir)
-               write_header("0", '5', NULL, NULL, basedir, 040755, 0);
+               write_header((unsigned char *)"0", TYPEFLAG_DIR, NULL, NULL,
+                       basedir, 040755, NULL, 0);
        traverse_tree(buffer, size, NULL);
        free(buffer);
        write_trailer();