tar-tree: Introduce write_entry()

[thirdparty/git.git] / tar-tree.c

diff --git a/tar-tree.c b/tar-tree.c
index 32f226ea5c30895df5bd21e28fcdf5e15ca3980e..37cd336929e38b40220d958665342e4070de68b3 100644 (file)
--- a/tar-tree.c
+++ b/tar-tree.c
@@ -1,21 +1,16 @@
 /*
- * Copyright (c) 2005 Rene Scharfe
+ * Copyright (c) 2005, 2006 Rene Scharfe
  */
 #include <time.h>
 #include "cache.h"
 #include "diff.h"
 #include "commit.h"
+#include "strbuf.h"
+#include "tar.h"
 
 #define RECORDSIZE     (512)
 #define BLOCKSIZE      (RECORDSIZE * 20)
 
-#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
 
@@ -119,6 +114,127 @@ static void write_blocked(void *buf, unsigned long size)
        write_if_needed();
 }
 
+/*
+ * pax extended header records have the format "%u %s=%s\n".  %u contains
+ * the size of the whole string (including the %u), the first %s is the
+ * keyword, the second one is the value.  This function constructs such a
+ * string and appends it to a struct strbuf.
+ */
+static void strbuf_append_ext_header(struct strbuf *sb, const char *keyword,
+                                     const char *value, unsigned int valuelen)
+{
+       char *p;
+       int len, total, tmp;
+
+       /* "%u %s=%s\n" */
+       len = 1 + 1 + strlen(keyword) + 1 + valuelen + 1;
+       for (tmp = len; tmp > 9; tmp /= 10)
+               len++;
+
+       total = sb->len + len;
+       if (total > sb->alloc) {
+               sb->buf = xrealloc(sb->buf, total);
+               sb->alloc = total;
+       }
+
+       p = sb->buf;
+       p += sprintf(p, "%u %s=", len, keyword);
+       memcpy(p, value, valuelen);
+       p += valuelen;
+       *p = '\n';
+       sb->len = total;
+}
+
+static unsigned int ustar_header_chksum(const struct ustar_header *header)
+{
+       char *p = (char *)header;
+       unsigned int chksum = 0;
+       while (p < header->chksum)
+               chksum += *p++;
+       chksum += sizeof(header->chksum) * ' ';
+       p += sizeof(header->chksum);
+       while (p < (char *)header + sizeof(struct ustar_header))
+               chksum += *p++;
+       return chksum;
+}
+
+static void write_entry(const unsigned char *sha1, struct strbuf *path,
+                        unsigned int mode, void *buffer, unsigned long size)
+{
+       struct ustar_header header;
+       struct strbuf ext_header;
+
+       memset(&header, 0, sizeof(header));
+       ext_header.buf = NULL;
+       ext_header.len = ext_header.alloc = 0;
+
+       if (!sha1) {
+               *header.typeflag = TYPEFLAG_GLOBAL_HEADER;
+               mode = 0100666;
+               strcpy(header.name, "pax_global_header");
+       } else if (!path) {
+               *header.typeflag = TYPEFLAG_EXT_HEADER;
+               mode = 0100666;
+               sprintf(header.name, "%s.paxheader", sha1_to_hex(sha1));
+       } else {
+               if (S_ISDIR(mode)) {
+                       *header.typeflag = TYPEFLAG_DIR;
+                       mode |= 0777;
+               } else if (S_ISLNK(mode)) {
+                       *header.typeflag = TYPEFLAG_LNK;
+                       mode |= 0777;
+               } else if (S_ISREG(mode)) {
+                       *header.typeflag = TYPEFLAG_REG;
+                       mode |= (mode & 0100) ? 0777 : 0666;
+               } else {
+                       error("unsupported file mode: 0%o (SHA1: %s)",
+                             mode, sha1_to_hex(sha1));
+                       return;
+               }
+               if (path->len > sizeof(header.name)) {
+                       sprintf(header.name, "%s.data", sha1_to_hex(sha1));
+                       strbuf_append_ext_header(&ext_header, "path",
+                                                path->buf, path->len);
+               } else
+                       memcpy(header.name, path->buf, path->len);
+       }
+
+       if (S_ISLNK(mode) && buffer) {
+               if (size > sizeof(header.linkname)) {
+                       sprintf(header.linkname, "see %s.paxheader",
+                               sha1_to_hex(sha1));
+                       strbuf_append_ext_header(&ext_header, "linkpath",
+                                                buffer, size);
+               } else
+                       memcpy(header.linkname, buffer, size);
+       }
+
+       sprintf(header.mode, "%07o", mode & 07777);
+       sprintf(header.size, "%011lo", S_ISREG(mode) ? size : 0);
+       sprintf(header.mtime, "%011lo", archive_time);
+
+       /* XXX: should we provide more meaningful info here? */
+       sprintf(header.uid, "%07o", 0);
+       sprintf(header.gid, "%07o", 0);
+       strncpy(header.uname, "git", 31);
+       strncpy(header.gname, "git", 31);
+       sprintf(header.devmajor, "%07o", 0);
+       sprintf(header.devminor, "%07o", 0);
+
+       memcpy(header.magic, "ustar", 6);
+       memcpy(header.version, "00", 2);
+
+       sprintf(header.chksum, "%07o", ustar_header_chksum(&header));
+
+       if (ext_header.len > 0) {
+               write_entry(sha1, NULL, 0, ext_header.buf, ext_header.len);
+               free(ext_header.buf);
+       }
+       write_blocked(&header, sizeof(header));
+       if (S_ISREG(mode) && buffer && size > 0)
+               write_blocked(buffer, size);
+}
+
 static void append_string(char **p, const char *s)
 {
        unsigned int len = strlen(s);
@@ -237,16 +353,12 @@ static void write_extended_header(const char *headerfilename, int is_dir,
 
 static void write_global_extended_header(const unsigned char *sha1)
 {
-       char *p;
-       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();
+       struct strbuf ext_header;
+       ext_header.buf = NULL;
+       ext_header.len = ext_header.alloc = 0;
+       strbuf_append_ext_header(&ext_header, "comment", sha1_to_hex(sha1), 40);
+       write_entry(NULL, NULL, 0, ext_header.buf, ext_header.len);
+       free(ext_header.buf);
 }
 
 /* stores a ustar header directly in the block buffer */