Imported Upstream version 2.13.2
[platform/upstream/git.git] / archive-tar.c
index 20af005..380e3ae 100644 (file)
@@ -4,6 +4,7 @@
 #include "cache.h"
 #include "tar.h"
 #include "archive.h"
+#include "streaming.h"
 #include "run-command.h"
 
 #define RECORDSIZE     (512)
@@ -17,6 +18,21 @@ static int tar_umask = 002;
 static int write_tar_filter_archive(const struct archiver *ar,
                                    struct archiver_args *args);
 
+/*
+ * This is the max value that a ustar size header can specify, as it is fixed
+ * at 11 octal digits. POSIX specifies that we switch to extended headers at
+ * this size.
+ *
+ * Likewise for the mtime (which happens to use a buffer of the same size).
+ */
+#if ULONG_MAX == 0xFFFFFFFF
+#define USTAR_MAX_SIZE ULONG_MAX
+#define USTAR_MAX_MTIME ULONG_MAX
+#else
+#define USTAR_MAX_SIZE 077777777777UL
+#define USTAR_MAX_MTIME 077777777777UL
+#endif
+
 /* writes out the whole block, but only if it is full */
 static void write_if_needed(void)
 {
@@ -30,10 +46,9 @@ static void write_if_needed(void)
  * queues up writes, so that all our write(2) calls write exactly one
  * full block; pads writes to RECORDSIZE
  */
-static void write_blocked(const void *data, unsigned long size)
+static void do_write_blocked(const void *data, unsigned long size)
 {
        const char *buf = data;
-       unsigned long tail;
 
        if (offset) {
                unsigned long chunk = BLOCKSIZE - offset;
@@ -54,6 +69,11 @@ static void write_blocked(const void *data, unsigned long size)
                memcpy(block + offset, buf, size);
                offset += size;
        }
+}
+
+static void finish_record(void)
+{
+       unsigned long tail;
        tail = offset % RECORDSIZE;
        if (tail)  {
                memset(block + offset, 0, RECORDSIZE - tail);
@@ -62,6 +82,12 @@ static void write_blocked(const void *data, unsigned long size)
        write_if_needed();
 }
 
+static void write_blocked(const void *data, unsigned long size)
+{
+       do_write_blocked(data, size);
+       finish_record();
+}
+
 /*
  * The end of tar archives is marked by 2*512 nul bytes and after that
  * follows the rest of the block (if any).
@@ -78,6 +104,33 @@ static void write_trailer(void)
 }
 
 /*
+ * queues up writes, so that all our write(2) calls write exactly one
+ * full block; pads writes to RECORDSIZE
+ */
+static int stream_blocked(const unsigned char *sha1)
+{
+       struct git_istream *st;
+       enum object_type type;
+       unsigned long sz;
+       char buf[BLOCKSIZE];
+       ssize_t readlen;
+
+       st = open_istream(sha1, &type, &sz, NULL);
+       if (!st)
+               return error("cannot stream blob %s", sha1_to_hex(sha1));
+       for (;;) {
+               readlen = read_istream(st, buf, sizeof(buf));
+               if (readlen <= 0)
+                       break;
+               do_write_blocked(buf, readlen);
+       }
+       close_istream(st);
+       if (!readlen)
+               finish_record();
+       return readlen;
+}
+
+/*
  * 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
@@ -99,15 +152,29 @@ static void strbuf_append_ext_header(struct strbuf *sb, const char *keyword,
        strbuf_addch(sb, '\n');
 }
 
+/*
+ * Like strbuf_append_ext_header, but for numeric values.
+ */
+static void strbuf_append_ext_header_uint(struct strbuf *sb,
+                                         const char *keyword,
+                                         uintmax_t value)
+{
+       char buf[40]; /* big enough for 2^128 in decimal, plus NUL */
+       int len;
+
+       len = xsnprintf(buf, sizeof(buf), "%"PRIuMAX, value);
+       strbuf_append_ext_header(sb, keyword, buf, len);
+}
+
 static unsigned int ustar_header_chksum(const struct ustar_header *header)
 {
-       char *p = (char *)header;
+       const unsigned char *p = (const unsigned char *)header;
        unsigned int chksum = 0;
-       while (p < header->chksum)
+       while (p < (const unsigned char *)header->chksum)
                chksum += *p++;
        chksum += sizeof(header->chksum) * ' ';
        p += sizeof(header->chksum);
-       while (p < (char *)header + sizeof(struct ustar_header))
+       while (p < (const unsigned char *)header + sizeof(struct ustar_header))
                chksum += *p++;
        return chksum;
 }
@@ -115,6 +182,8 @@ static unsigned int ustar_header_chksum(const struct ustar_header *header)
 static size_t get_path_prefix(const char *path, size_t pathlen, size_t maxlen)
 {
        size_t i = pathlen;
+       if (i > 1 && path[i - 1] == '/')
+               i--;
        if (i > maxlen)
                i = maxlen;
        do {
@@ -123,105 +192,160 @@ static size_t get_path_prefix(const char *path, size_t pathlen, size_t maxlen)
        return i;
 }
 
+static void prepare_header(struct archiver_args *args,
+                          struct ustar_header *header,
+                          unsigned int mode, unsigned long size)
+{
+       xsnprintf(header->mode, sizeof(header->mode), "%07o", mode & 07777);
+       xsnprintf(header->size, sizeof(header->size), "%011lo", S_ISREG(mode) ? size : 0);
+       xsnprintf(header->mtime, sizeof(header->mtime), "%011lo", (unsigned long) args->time);
+
+       xsnprintf(header->uid, sizeof(header->uid), "%07o", 0);
+       xsnprintf(header->gid, sizeof(header->gid), "%07o", 0);
+       strlcpy(header->uname, "root", sizeof(header->uname));
+       strlcpy(header->gname, "root", sizeof(header->gname));
+       xsnprintf(header->devmajor, sizeof(header->devmajor), "%07o", 0);
+       xsnprintf(header->devminor, sizeof(header->devminor), "%07o", 0);
+
+       memcpy(header->magic, "ustar", 6);
+       memcpy(header->version, "00", 2);
+
+       xsnprintf(header->chksum, sizeof(header->chksum), "%07o", ustar_header_chksum(header));
+}
+
+static void write_extended_header(struct archiver_args *args,
+                                 const unsigned char *sha1,
+                                 const void *buffer, unsigned long size)
+{
+       struct ustar_header header;
+       unsigned int mode;
+       memset(&header, 0, sizeof(header));
+       *header.typeflag = TYPEFLAG_EXT_HEADER;
+       mode = 0100666;
+       xsnprintf(header.name, sizeof(header.name), "%s.paxheader", sha1_to_hex(sha1));
+       prepare_header(args, &header, mode, size);
+       write_blocked(&header, sizeof(header));
+       write_blocked(buffer, size);
+}
+
 static int write_tar_entry(struct archiver_args *args,
-               const unsigned char *sha1, const char *path, size_t pathlen,
-               unsigned int mode, void *buffer, unsigned long size)
+                          const unsigned char *sha1,
+                          const char *path, size_t pathlen,
+                          unsigned int mode)
 {
        struct ustar_header header;
        struct strbuf ext_header = STRBUF_INIT;
+       unsigned int old_mode = mode;
+       unsigned long size, size_in_header;
+       void *buffer;
        int err = 0;
 
        memset(&header, 0, sizeof(header));
 
-       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));
+       if (S_ISDIR(mode) || S_ISGITLINK(mode)) {
+               *header.typeflag = TYPEFLAG_DIR;
+               mode = (mode | 0777) & ~tar_umask;
+       } else if (S_ISLNK(mode)) {
+               *header.typeflag = TYPEFLAG_LNK;
+               mode |= 0777;
+       } else if (S_ISREG(mode)) {
+               *header.typeflag = TYPEFLAG_REG;
+               mode = (mode | ((mode & 0100) ? 0777 : 0666)) & ~tar_umask;
        } else {
-               if (S_ISDIR(mode) || S_ISGITLINK(mode)) {
-                       *header.typeflag = TYPEFLAG_DIR;
-                       mode = (mode | 0777) & ~tar_umask;
-               } else if (S_ISLNK(mode)) {
-                       *header.typeflag = TYPEFLAG_LNK;
-                       mode |= 0777;
-               } else if (S_ISREG(mode)) {
-                       *header.typeflag = TYPEFLAG_REG;
-                       mode = (mode | ((mode & 0100) ? 0777 : 0666)) & ~tar_umask;
+               return error("unsupported file mode: 0%o (SHA1: %s)",
+                            mode, sha1_to_hex(sha1));
+       }
+       if (pathlen > sizeof(header.name)) {
+               size_t plen = get_path_prefix(path, pathlen,
+                                             sizeof(header.prefix));
+               size_t rest = pathlen - plen - 1;
+               if (plen > 0 && rest <= sizeof(header.name)) {
+                       memcpy(header.prefix, path, plen);
+                       memcpy(header.name, path + plen + 1, rest);
                } else {
-                       return error("unsupported file mode: 0%o (SHA1: %s)",
-                                       mode, sha1_to_hex(sha1));
+                       xsnprintf(header.name, sizeof(header.name), "%s.data",
+                                 sha1_to_hex(sha1));
+                       strbuf_append_ext_header(&ext_header, "path",
+                                                path, pathlen);
                }
-               if (pathlen > sizeof(header.name)) {
-                       size_t plen = get_path_prefix(path, pathlen,
-                                       sizeof(header.prefix));
-                       size_t rest = pathlen - plen - 1;
-                       if (plen > 0 && rest <= sizeof(header.name)) {
-                               memcpy(header.prefix, path, plen);
-                               memcpy(header.name, path + plen + 1, rest);
-                       } else {
-                               sprintf(header.name, "%s.data",
-                                       sha1_to_hex(sha1));
-                               strbuf_append_ext_header(&ext_header, "path",
-                                               path, pathlen);
-                       }
-               } else
-                       memcpy(header.name, path, pathlen);
+       } else
+               memcpy(header.name, path, pathlen);
+
+       if (S_ISREG(mode) && !args->convert &&
+           sha1_object_info(sha1, &size) == OBJ_BLOB &&
+           size > big_file_threshold)
+               buffer = NULL;
+       else if (S_ISLNK(mode) || S_ISREG(mode)) {
+               enum object_type type;
+               buffer = sha1_file_to_archive(args, path, sha1, old_mode, &type, &size);
+               if (!buffer)
+                       return error("cannot read %s", sha1_to_hex(sha1));
+       } else {
+               buffer = NULL;
+               size = 0;
        }
 
-       if (S_ISLNK(mode) && buffer) {
+       if (S_ISLNK(mode)) {
                if (size > sizeof(header.linkname)) {
-                       sprintf(header.linkname, "see %s.paxheader",
-                               sha1_to_hex(sha1));
+                       xsnprintf(header.linkname, sizeof(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", (unsigned long) args->time);
-
-       sprintf(header.uid, "%07o", 0);
-       sprintf(header.gid, "%07o", 0);
-       strlcpy(header.uname, "root", sizeof(header.uname));
-       strlcpy(header.gname, "root", sizeof(header.gname));
-       sprintf(header.devmajor, "%07o", 0);
-       sprintf(header.devminor, "%07o", 0);
-
-       memcpy(header.magic, "ustar", 6);
-       memcpy(header.version, "00", 2);
+       size_in_header = size;
+       if (S_ISREG(mode) && size > USTAR_MAX_SIZE) {
+               size_in_header = 0;
+               strbuf_append_ext_header_uint(&ext_header, "size", size);
+       }
 
-       sprintf(header.chksum, "%07o", ustar_header_chksum(&header));
+       prepare_header(args, &header, mode, size_in_header);
 
        if (ext_header.len > 0) {
-               err = write_tar_entry(args, sha1, NULL, 0, 0, ext_header.buf,
-                               ext_header.len);
-               if (err)
-                       return err;
+               write_extended_header(args, sha1, ext_header.buf,
+                                     ext_header.len);
        }
        strbuf_release(&ext_header);
        write_blocked(&header, sizeof(header));
-       if (S_ISREG(mode) && buffer && size > 0)
-               write_blocked(buffer, size);
+       if (S_ISREG(mode) && size > 0) {
+               if (buffer)
+                       write_blocked(buffer, size);
+               else
+                       err = stream_blocked(sha1);
+       }
+       free(buffer);
        return err;
 }
 
-static int write_global_extended_header(struct archiver_args *args)
+static void write_global_extended_header(struct archiver_args *args)
 {
        const unsigned char *sha1 = args->commit_sha1;
        struct strbuf ext_header = STRBUF_INIT;
-       int err;
+       struct ustar_header header;
+       unsigned int mode;
+
+       if (sha1)
+               strbuf_append_ext_header(&ext_header, "comment",
+                                        sha1_to_hex(sha1), 40);
+       if (args->time > USTAR_MAX_MTIME) {
+               strbuf_append_ext_header_uint(&ext_header, "mtime",
+                                             args->time);
+               args->time = USTAR_MAX_MTIME;
+       }
 
-       strbuf_append_ext_header(&ext_header, "comment", sha1_to_hex(sha1), 40);
-       err = write_tar_entry(args, NULL, NULL, 0, 0, ext_header.buf,
-                       ext_header.len);
+       if (!ext_header.len)
+               return;
+
+       memset(&header, 0, sizeof(header));
+       *header.typeflag = TYPEFLAG_GLOBAL_HEADER;
+       mode = 0100666;
+       xsnprintf(header.name, sizeof(header.name), "pax_global_header");
+       prepare_header(args, &header, mode, ext_header.len);
+       write_blocked(&header, sizeof(header));
+       write_blocked(ext_header.buf, ext_header.len);
        strbuf_release(&ext_header);
-       return err;
 }
 
 static struct archiver **tar_filters;
@@ -242,20 +366,12 @@ static struct archiver *find_tar_filter(const char *name, int len)
 static int tar_filter_config(const char *var, const char *value, void *data)
 {
        struct archiver *ar;
-       const char *dot;
        const char *name;
        const char *type;
        int namelen;
 
-       if (prefixcmp(var, "tar."))
+       if (parse_config_key(var, "tar", &name, &namelen, &type) < 0 || !name)
                return 0;
-       dot = strrchr(var, '.');
-       if (dot == var + 9)
-               return 0;
-
-       name = var + 4;
-       namelen = dot - name;
-       type = dot + 1;
 
        ar = find_tar_filter(name, namelen);
        if (!ar) {
@@ -305,10 +421,8 @@ static int write_tar_archive(const struct archiver *ar,
 {
        int err = 0;
 
-       if (args->commit_sha1)
-               err = write_global_extended_header(args);
-       if (!err)
-               err = write_archive_entries(args, write_tar_entry);
+       write_global_extended_header(args);
+       err = write_archive_entries(args, write_tar_entry);
        if (!err)
                write_trailer();
        return err;
@@ -318,7 +432,7 @@ static int write_tar_filter_archive(const struct archiver *ar,
                                    struct archiver_args *args)
 {
        struct strbuf cmd = STRBUF_INIT;
-       struct child_process filter;
+       struct child_process filter = CHILD_PROCESS_INIT;
        const char *argv[2];
        int r;
 
@@ -329,7 +443,6 @@ static int write_tar_filter_archive(const struct archiver *ar,
        if (args->compression_level >= 0)
                strbuf_addf(&cmd, " -%d", args->compression_level);
 
-       memset(&filter, 0, sizeof(filter));
        argv[0] = cmd.buf;
        argv[1] = NULL;
        filter.argv = argv;