builtin/hash-object.c

   1 /*
   2  * GIT - The information manager from hell
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  * Copyright (C) Junio C Hamano, 2005
   6  */
   7 #include "builtin.h"
   8 #include "blob.h"
   9 #include "quote.h"
  10 #include "parse-options.h"
  11 #include "exec_cmd.h"
  12
  13 /*
  14  * This is to create corrupt objects for debugging and as such it
  15  * needs to bypass the data conversion performed by, and the type
  16  * limitation imposed by, index_fd() and its callees.
  17  */
  18 static int hash_literally(unsigned char *sha1, int fd, const char *type, unsigned flags)
  19 {
  20         struct strbuf buf = STRBUF_INIT;
  21         int ret;
  22
  23         if (strbuf_read(&buf, fd, 4096) < 0)
  24                 ret = -1;
  25         else if (flags & HASH_WRITE_OBJECT)
  26                 ret = write_sha1_file(buf.buf, buf.len, type, sha1);
  27         else
  28                 ret = hash_sha1_file(buf.buf, buf.len, type, sha1);
  29         strbuf_release(&buf);
  30         return ret;
  31 }
  32
  33 static void hash_fd(int fd, const char *type, const char *path, unsigned flags,
  34                     int literally)
  35 {
  36         struct stat st;
  37         unsigned char sha1[20];
  38
  39         if (fstat(fd, &st) < 0 ||
  40             (literally
  41              ? hash_literally(sha1, fd, type, flags)
  42              : index_fd(sha1, fd, &st, type_from_string(type), path, flags)))
  43                 die((flags & HASH_WRITE_OBJECT)
  44                     ? "Unable to add %s to database"
  45                     : "Unable to hash %s", path);
  46         printf("%s\n", sha1_to_hex(sha1));
  47         maybe_flush_or_die(stdout, "hash to stdout");
  48 }
  49
  50 static void hash_object(const char *path, const char *type, const char *vpath,
  51                         unsigned flags, int literally)
  52 {
  53         int fd;
  54         fd = open(path, O_RDONLY);
  55         if (fd < 0)
  56                 die_errno("Cannot open '%s'", path);
  57         hash_fd(fd, type, vpath, flags, literally);
  58 }
  59
  60 static void hash_stdin_paths(const char *type, int no_filters, unsigned flags,
  61                              int literally)
  62 {
  63         struct strbuf buf = STRBUF_INIT, nbuf = STRBUF_INIT;
  64
  65         while (strbuf_getline(&buf, stdin, '\n') != EOF) {
  66                 if (buf.buf[0] == '"') {
  67                         strbuf_reset(&nbuf);
  68                         if (unquote_c_style(&nbuf, buf.buf, NULL))
  69                                 die("line is badly quoted");
  70                         strbuf_swap(&buf, &nbuf);
  71                 }
  72                 hash_object(buf.buf, type, no_filters ? NULL : buf.buf, flags,
  73                             literally);
  74         }
  75         strbuf_release(&buf);
  76         strbuf_release(&nbuf);
  77 }
  78
  79 int cmd_hash_object(int argc, const char **argv, const char *prefix)
  80 {
  81         static const char * const hash_object_usage[] = {
  82                 N_("git hash-object [-t <type>] [-w] [--path=<file> | --no-filters] [--stdin] [--] <file>..."),
  83                 N_("git hash-object  --stdin-paths < <list-of-paths>"),
  84                 NULL
  85         };
  86         const char *type = blob_type;
  87         int hashstdin = 0;
  88         int stdin_paths = 0;
  89         int no_filters = 0;
  90         int literally = 0;
  91         unsigned flags = HASH_FORMAT_CHECK;
  92         const char *vpath = NULL;
  93         const struct option hash_object_options[] = {
  94                 OPT_STRING('t', NULL, &type, N_("type"), N_("object type")),
  95                 OPT_BIT('w', NULL, &flags, N_("write the object into the object database"),
  96                         HASH_WRITE_OBJECT),
  97                 OPT_COUNTUP( 0 , "stdin", &hashstdin, N_("read the object from stdin")),
  98                 OPT_BOOL( 0 , "stdin-paths", &stdin_paths, N_("read file names from stdin")),
  99                 OPT_BOOL( 0 , "no-filters", &no_filters, N_("store file as is without filters")),
 100                 OPT_BOOL( 0, "literally", &literally, N_("just hash any random garbage to create corrupt objects for debugging Git")),
 101                 OPT_STRING( 0 , "path", &vpath, N_("file"), N_("process file as it were from this path")),
 102                 OPT_END()
 103         };
 104         int i;
 105         int prefix_length = -1;
 106         const char *errstr = NULL;
 107
 108         argc = parse_options(argc, argv, NULL, hash_object_options,
 109                              hash_object_usage, 0);
 110
 111         if (flags & HASH_WRITE_OBJECT) {
 112                 prefix = setup_git_directory();
 113                 prefix_length = prefix ? strlen(prefix) : 0;
 114                 if (vpath && prefix)
 115                         vpath = prefix_filename(prefix, prefix_length, vpath);
 116         }
 117
 118         git_config(git_default_config, NULL);
 119
 120         if (stdin_paths) {
 121                 if (hashstdin)
 122                         errstr = "Can't use --stdin-paths with --stdin";
 123                 else if (argc)
 124                         errstr = "Can't specify files with --stdin-paths";
 125                 else if (vpath)
 126                         errstr = "Can't use --stdin-paths with --path";
 127         }
 128         else {
 129                 if (hashstdin > 1)
 130                         errstr = "Multiple --stdin arguments are not supported";
 131                 if (vpath && no_filters)
 132                         errstr = "Can't use --path with --no-filters";
 133         }
 134
 135         if (errstr) {
 136                 error("%s", errstr);
 137                 usage_with_options(hash_object_usage, hash_object_options);
 138         }
 139
 140         if (hashstdin)
 141                 hash_fd(0, type, vpath, flags, literally);
 142
 143         for (i = 0 ; i < argc; i++) {
 144                 const char *arg = argv[i];
 145
 146                 if (0 <= prefix_length)
 147                         arg = prefix_filename(prefix, prefix_length, arg);
 148                 hash_object(arg, type, no_filters ? NULL : vpath ? vpath : arg,
 149                             flags, literally);
 150         }
 151
 152         if (stdin_paths)
 153                 hash_stdin_paths(type, no_filters, flags, literally);
 154
 155         return 0;
 156 }