Merge branch 'db/text-delta' into svn-fe
[gitweb.git] / vcs-svn / fast_export.c
index ec323e9b3917307abf96a111b7fe5aa40c2a56df..3efde20a0cac6309e51a51745be8919ee63dccde 100644 (file)
@@ -7,15 +7,28 @@
 #include "strbuf.h"
 #include "quote.h"
 #include "fast_export.h"
-#include "line_buffer.h"
 #include "repo_tree.h"
 #include "strbuf.h"
+#include "svndiff.h"
+#include "sliding_window.h"
+#include "line_buffer.h"
 
 #define MAX_GITSVN_LINE_LEN 4096
 
 static uint32_t first_commit_done;
+static struct line_buffer postimage = LINE_BUFFER_INIT;
 static struct line_buffer report_buffer = LINE_BUFFER_INIT;
 
+/* NEEDSWORK: move to fast_export_init() */
+static int init_postimage(void)
+{
+       static int postimage_initialized;
+       if (postimage_initialized)
+               return 0;
+       postimage_initialized = 1;
+       return buffer_tmpfile_init(&postimage);
+}
+
 void fast_export_init(int fd)
 {
        if (buffer_fdinit(&report_buffer, fd))
@@ -60,12 +73,14 @@ void fast_export_modify(const char *path, uint32_t mode, const char *dataref)
 }
 
 static char gitsvnline[MAX_GITSVN_LINE_LEN];
-void fast_export_begin_commit(uint32_t revision, const char *author, char *log,
+void fast_export_begin_commit(uint32_t revision, const char *author,
+                       const struct strbuf *log,
                        const char *uuid, const char *url,
                        unsigned long timestamp)
 {
+       static const struct strbuf empty = STRBUF_INIT;
        if (!log)
-               log = "";
+               log = ∅
        if (*uuid && *url) {
                snprintf(gitsvnline, MAX_GITSVN_LINE_LEN,
                                "\n\ngit-svn-id: %s@%"PRIu32" %s\n",
@@ -79,9 +94,10 @@ void fast_export_begin_commit(uint32_t revision, const char *author, char *log,
                   *author ? author : "nobody",
                   *author ? author : "nobody",
                   *uuid ? uuid : "local", timestamp);
-       printf("data %"PRIu32"\n%s%s\n",
-                  (uint32_t) (strlen(log) + strlen(gitsvnline)),
-                  log, gitsvnline);
+       printf("data %"PRIuMAX"\n",
+               (uintmax_t) (log->len + strlen(gitsvnline)));
+       fwrite(log->buf, log->len, 1, stdout);
+       printf("%s\n", gitsvnline);
        if (!first_commit_done) {
                if (revision > 1)
                        printf("from :%"PRIu32"\n", revision - 1);
@@ -129,6 +145,87 @@ static void die_short_read(struct line_buffer *input)
        die("invalid dump: unexpected end of file");
 }
 
+static int ends_with(const char *s, size_t len, const char *suffix)
+{
+       const size_t suffixlen = strlen(suffix);
+       if (len < suffixlen)
+               return 0;
+       return !memcmp(s + len - suffixlen, suffix, suffixlen);
+}
+
+static int parse_cat_response_line(const char *header, off_t *len)
+{
+       size_t headerlen = strlen(header);
+       uintmax_t n;
+       const char *type;
+       const char *end;
+
+       if (ends_with(header, headerlen, " missing"))
+               return error("cat-blob reports missing blob: %s", header);
+       type = memmem(header, headerlen, " blob ", strlen(" blob "));
+       if (!type)
+               return error("cat-blob header has wrong object type: %s", header);
+       n = strtoumax(type + strlen(" blob "), (char **) &end, 10);
+       if (end == type + strlen(" blob "))
+               return error("cat-blob header does not contain length: %s", header);
+       if (memchr(type + strlen(" blob "), '-', end - type - strlen(" blob ")))
+               return error("cat-blob header contains negative length: %s", header);
+       if (n == UINTMAX_MAX || n > maximum_signed_value_of_type(off_t))
+               return error("blob too large for current definition of off_t");
+       *len = n;
+       if (*end)
+               return error("cat-blob header contains garbage after length: %s", header);
+       return 0;
+}
+
+static void check_preimage_overflow(off_t a, off_t b)
+{
+       if (signed_add_overflows(a, b))
+               die("blob too large for current definition of off_t");
+}
+
+static long apply_delta(off_t len, struct line_buffer *input,
+                       const char *old_data, uint32_t old_mode)
+{
+       long ret;
+       struct sliding_view preimage = SLIDING_VIEW_INIT(&report_buffer, 0);
+       FILE *out;
+
+       if (init_postimage() || !(out = buffer_tmpfile_rewind(&postimage)))
+               die("cannot open temporary file for blob retrieval");
+       if (old_data) {
+               const char *response;
+               printf("cat-blob %s\n", old_data);
+               fflush(stdout);
+               response = get_response_line();
+               if (parse_cat_response_line(response, &preimage.max_off))
+                       die("invalid cat-blob response: %s", response);
+               check_preimage_overflow(preimage.max_off, 1);
+       }
+       if (old_mode == REPO_MODE_LNK) {
+               strbuf_addstr(&preimage.buf, "link ");
+               check_preimage_overflow(preimage.max_off, strlen("link "));
+               preimage.max_off += strlen("link ");
+               check_preimage_overflow(preimage.max_off, 1);
+       }
+       if (svndiff0_apply(input, len, &preimage, out))
+               die("cannot apply delta");
+       if (old_data) {
+               /* Read the remainder of preimage and trailing newline. */
+               assert(!signed_add_overflows(preimage.max_off, 1));
+               preimage.max_off++;     /* room for newline */
+               if (move_window(&preimage, preimage.max_off - 1, 1))
+                       die("cannot seek to end of input");
+               if (preimage.buf.buf[0] != '\n')
+                       die("missing newline after cat-blob response");
+       }
+       ret = buffer_tmpfile_prepare_to_read(&postimage);
+       if (ret < 0)
+               die("cannot read temporary file for blob retrieval");
+       strbuf_release(&preimage.buf);
+       return ret;
+}
+
 void fast_export_data(uint32_t mode, uint32_t len, struct line_buffer *input)
 {
        if (mode == REPO_MODE_LNK) {
@@ -196,3 +293,20 @@ int fast_export_ls(const char *path, uint32_t *mode, struct strbuf *dataref)
        ls_from_active_commit(path);
        return parse_ls_response(get_response_line(), mode, dataref);
 }
+
+void fast_export_blob_delta(uint32_t mode,
+                               uint32_t old_mode, const char *old_data,
+                               uint32_t len, struct line_buffer *input)
+{
+       long postimage_len;
+       if (len > maximum_signed_value_of_type(off_t))
+               die("enormous delta");
+       postimage_len = apply_delta((off_t) len, input, old_data, old_mode);
+       if (mode == REPO_MODE_LNK) {
+               buffer_skip_bytes(&postimage, strlen("link "));
+               postimage_len -= strlen("link ");
+       }
+       printf("data %ld\n", postimage_len);
+       buffer_copy_bytes(&postimage, postimage_len);
+       fputc('\n', stdout);
+}