archive-tar: stream large blobs to tar file

t5000 verifies output while t1050 makes sure the command always
respects core.bigfilethreshold

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/archive-tar.c b/archive-tar.c
index 3be0cdf..93387ea 100644 (file)
--- a/archive-tar.c
+++ b/archive-tar.c
@@ -4,6 +4,7 @@
 #include "cache.h"
 #include "tar.h"
 #include "archive.h"
+#include "streaming.h"
 #include "run-command.h"
 
 #define RECORDSIZE     (512)
@@ -30,10 +31,9 @@ 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 +54,11 @@ 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 +67,12 @@ 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 +89,33 @@ 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
@@ -203,7 +241,11 @@ static int write_tar_entry(struct archiver_args *args,
        } else
                memcpy(header.name, path, pathlen);
 
-       if (S_ISLNK(mode) || S_ISREG(mode)) {
+       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)
@@ -235,8 +277,12 @@ static int write_tar_entry(struct archiver_args *args,
        }
        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;
 }

diff --git a/t/t1050-large.sh b/t/t1050-large.sh
index 4d127f1..fe47554 100755 (executable)
--- a/t/t1050-large.sh
+++ b/t/t1050-large.sh
@@ -134,4 +134,8 @@ test_expect_success 'repack' '
        git repack -ad
 '
 
+test_expect_success 'tar achiving' '
+       git archive --format=tar HEAD >/dev/null
+'
+
 test_done

diff --git a/t/t5000-tar-tree.sh b/t/t5000-tar-tree.sh
index 527c9e7..d9b997f 100755 (executable)
--- a/t/t5000-tar-tree.sh
+++ b/t/t5000-tar-tree.sh
@@ -84,6 +84,12 @@ test_expect_success \
     'git archive vs. git tar-tree' \
     'test_cmp b.tar b2.tar'
 
+test_expect_success 'git archive on large files' '
+    test_config core.bigfilethreshold 1 &&
+    git archive HEAD >b3.tar &&
+    test_cmp b.tar b3.tar
+'
+
 test_expect_success \
     'git archive in a bare repo' \
     '(cd bare.git && git archive HEAD) >b3.tar'