fetch: Speed up fetch of large numbers of refs
[gitweb.git] / combine-diff.c
index b3b86aebcb81972ca50a031f4e15bb7a905101e0..5b63af1eeb71907f23117bc552fa7a4019f09722 100644 (file)
@@ -6,6 +6,7 @@
 #include "quote.h"
 #include "xdiff-interface.h"
 #include "log-tree.h"
+#include "refs.h"
 
 static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr, int n, int num_parent)
 {
@@ -23,7 +24,7 @@ static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr,
                        path = q->queue[i]->two->path;
                        len = strlen(path);
                        p = xmalloc(combine_diff_path_size(num_parent, len));
-                       p->path = (char*) &(p->parent[num_parent]);
+                       p->path = (char *) &(p->parent[num_parent]);
                        memcpy(p->path, path, len);
                        p->path[len] = 0;
                        p->len = len;
@@ -79,6 +80,7 @@ struct lline {
 /* Lines surviving in the merge result */
 struct sline {
        struct lline *lost_head, **lost_tail;
+       struct lline *next_lost;
        char *bol;
        int len;
        /* bit 0 up to (N-1) are on if the parent has this line (i.e.
@@ -90,18 +92,24 @@ struct sline {
        unsigned long *p_lno;
 };
 
-static char *grab_blob(const unsigned char *sha1, unsigned long *size)
+static char *grab_blob(const unsigned char *sha1, unsigned int mode, unsigned long *size)
 {
        char *blob;
        enum object_type type;
-       if (is_null_sha1(sha1)) {
+
+       if (S_ISGITLINK(mode)) {
+               blob = xmalloc(100);
+               *size = snprintf(blob, 100,
+                                "Subproject commit %s\n", sha1_to_hex(sha1));
+       } else if (is_null_sha1(sha1)) {
                /* deleted blob */
                *size = 0;
                return xcalloc(1, 1);
+       } else {
+               blob = read_sha1_file(sha1, &type, size);
+               if (type != OBJ_BLOB)
+                       die("object '%s' is not a blob!", sha1_to_hex(sha1));
        }
-       blob = read_sha1_file(sha1, &type, size);
-       if (type != OBJ_BLOB)
-               die("object '%s' is not a blob!", sha1_to_hex(sha1));
        return blob;
 }
 
@@ -114,18 +122,12 @@ static void append_lost(struct sline *sline, int n, const char *line, int len)
 
        /* Check to see if we can squash things */
        if (sline->lost_head) {
-               struct lline *last_one = NULL;
-               /* We cannot squash it with earlier one */
-               for (lline = sline->lost_head;
-                    lline;
-                    lline = lline->next)
-                       if (lline->parent_map & this_mask)
-                               last_one = lline;
-               lline = last_one ? last_one->next : sline->lost_head;
+               lline = sline->next_lost;
                while (lline) {
                        if (lline->len == len &&
                            !memcmp(lline->line, line, len)) {
                                lline->parent_map |= this_mask;
+                               sline->next_lost = lline->next;
                                return;
                        }
                        lline = lline->next;
@@ -140,6 +142,7 @@ static void append_lost(struct sline *sline, int n, const char *line, int len)
        lline->line[len] = 0;
        *sline->lost_tail = lline;
        sline->lost_tail = &lline->next;
+       sline->next_lost = NULL;
 }
 
 struct combine_diff_state {
@@ -161,25 +164,28 @@ static void consume_line(void *state_, char *line, unsigned long len)
                                      &state->nb, &state->nn))
                        return;
                state->lno = state->nb;
-               if (!state->nb)
-                       /* @@ -1,2 +0,0 @@ to remove the
-                        * first two lines...
-                        */
-                       state->nb = 1;
-               if (state->nn == 0)
+               if (state->nn == 0) {
                        /* @@ -X,Y +N,0 @@ removed Y lines
                         * that would have come *after* line N
                         * in the result.  Our lost buckets hang
                         * to the line after the removed lines,
+                        *
+                        * Note that this is correct even when N == 0,
+                        * in which case the hunk removes the first
+                        * line in the file.
                         */
                        state->lost_bucket = &state->sline[state->nb];
-               else
+                       if (!state->nb)
+                               state->nb = 1;
+               } else {
                        state->lost_bucket = &state->sline[state->nb-1];
+               }
                if (!state->sline[state->nb-1].p_lno)
                        state->sline[state->nb-1].p_lno =
                                xcalloc(state->num_parent,
                                        sizeof(unsigned long));
                state->sline[state->nb-1].p_lno[state->n] = state->ob;
+               state->lost_bucket->next_lost = state->lost_bucket->lost_head;
                return;
        }
        if (!state->lost_bucket)
@@ -195,7 +201,8 @@ static void consume_line(void *state_, char *line, unsigned long len)
        }
 }
 
-static void combine_diff(const unsigned char *parent, mmfile_t *result_file,
+static void combine_diff(const unsigned char *parent, unsigned int mode,
+                        mmfile_t *result_file,
                         struct sline *sline, unsigned int cnt, int n,
                         int num_parent)
 {
@@ -211,7 +218,7 @@ static void combine_diff(const unsigned char *parent, mmfile_t *result_file,
        if (!cnt)
                return; /* result deleted */
 
-       parent_file.ptr = grab_blob(parent, &sz);
+       parent_file.ptr = grab_blob(parent, mode, &sz);
        parent_file.size = sz;
        memset(&xpp, 0, sizeof(xpp));
        xpp.flags = XDF_NEED_MINIMAL;
@@ -692,7 +699,7 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 
        /* Read the result of merge first */
        if (!working_tree_file)
-               result = grab_blob(elem->sha1, &result_size);
+               result = grab_blob(elem->sha1, elem->mode, &result_size);
        else {
                /* Used by diff-tree to read from the working tree */
                struct stat st;
@@ -712,9 +719,13 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
                        result_size = buf.len;
                        result = strbuf_detach(&buf, NULL);
                        elem->mode = canon_mode(st.st_mode);
-               }
-               else if (0 <= (fd = open(elem->path, O_RDONLY)) &&
-                        !fstat(fd, &st)) {
+               } else if (S_ISDIR(st.st_mode)) {
+                       unsigned char sha1[20];
+                       if (resolve_gitlink_ref(elem->path, "HEAD", sha1) < 0)
+                               result = grab_blob(elem->sha1, elem->mode, &result_size);
+                       else
+                               result = grab_blob(sha1, elem->mode, &result_size);
+               } else if (0 <= (fd = open(elem->path, O_RDONLY))) {
                        size_t len = xsize_t(st.st_size);
                        ssize_t done;
                        int is_file, i;
@@ -734,7 +745,7 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 
                        done = read_in_full(fd, result, len);
                        if (done < 0)
-                               die("read error '%s'", elem->path);
+                               die_errno("read error '%s'", elem->path);
                        else if (done < len)
                                die("early EOF '%s'", elem->path);
 
@@ -806,7 +817,9 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
                        }
                }
                if (i <= j)
-                       combine_diff(elem->parent[i].sha1, &result_file, sline,
+                       combine_diff(elem->parent[i].sha1,
+                                    elem->parent[i].mode,
+                                    &result_file, sline,
                                     cnt, i, num_parent);
                if (elem->parent[i].mode != elem->mode)
                        mode_differs = 1;
@@ -1049,7 +1062,7 @@ void diff_tree_combined_merge(const unsigned char *sha1,
        for (parents = commit->parents, num_parent = 0;
             parents;
             parents = parents->next, num_parent++)
-               hashcpy((unsigned char*)(parent + num_parent),
+               hashcpy((unsigned char *)(parent + num_parent),
                        parents->item->object.sha1);
        diff_tree_combined(sha1, parent, num_parent, dense, rev);
 }