tree-diff: no need to manually verify that there is no mode change for a path
[gitweb.git] / combine-diff.c
index 6288485965b5f79c1311e48e8de5c1be97730977..1732dfd110664e06924f465bdd50bc7a1d83ec2c 100644 (file)
 #include "refs.h"
 #include "userdiff.h"
 #include "sha1-array.h"
+#include "revision.h"
 
 static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr, int n, int num_parent)
 {
        struct diff_queue_struct *q = &diff_queued_diff;
-       struct combine_diff_path *p;
-       int i;
+       struct combine_diff_path *p, **tail = &curr;
+       int i, cmp;
 
        if (!n) {
-               struct combine_diff_path *list = NULL, **tail = &list;
                for (i = 0; i < q->nr; i++) {
                        int len;
                        const char *path;
@@ -30,7 +30,6 @@ static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr,
                        p->path = (char *) &(p->parent[num_parent]);
                        memcpy(p->path, path, len);
                        p->path[len] = 0;
-                       p->len = len;
                        p->next = NULL;
                        memset(p->parent, 0,
                               sizeof(p->parent[0]) * num_parent);
@@ -43,47 +42,61 @@ static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr,
                        *tail = p;
                        tail = &p->next;
                }
-               return list;
+               return curr;
        }
 
-       for (p = curr; p; p = p->next) {
-               int found = 0;
-               if (!p->len)
+       /*
+        * paths in curr (linked list) and q->queue[] (array) are
+        * both sorted in the tree order.
+        */
+       i = 0;
+       while ((p = *tail) != NULL) {
+               cmp = ((i >= q->nr)
+                      ? -1 : strcmp(p->path, q->queue[i]->two->path));
+
+               if (cmp < 0) {
+                       /* p->path not in q->queue[]; drop it */
+                       *tail = p->next;
+                       free(p);
                        continue;
-               for (i = 0; i < q->nr; i++) {
-                       const char *path;
-                       int len;
+               }
 
-                       if (diff_unmodified_pair(q->queue[i]))
-                               continue;
-                       path = q->queue[i]->two->path;
-                       len = strlen(path);
-                       if (len == p->len && !memcmp(path, p->path, len)) {
-                               found = 1;
-                               hashcpy(p->parent[n].sha1, q->queue[i]->one->sha1);
-                               p->parent[n].mode = q->queue[i]->one->mode;
-                               p->parent[n].status = q->queue[i]->status;
-                               break;
-                       }
+               if (cmp > 0) {
+                       /* q->queue[i] not in p->path; skip it */
+                       i++;
+                       continue;
                }
-               if (!found)
-                       p->len = 0;
+
+               hashcpy(p->parent[n].sha1, q->queue[i]->one->sha1);
+               p->parent[n].mode = q->queue[i]->one->mode;
+               p->parent[n].status = q->queue[i]->status;
+
+               tail = &p->next;
+               i++;
        }
        return curr;
 }
 
 /* Lines lost from parent */
 struct lline {
-       struct lline *next;
+       struct lline *next, *prev;
        int len;
        unsigned long parent_map;
        char line[FLEX_ARRAY];
 };
 
+/* Lines lost from current parent (before coalescing) */
+struct plost {
+       struct lline *lost_head, *lost_tail;
+       int len;
+};
+
 /* Lines surviving in the merge result */
 struct sline {
-       struct lline *lost_head, **lost_tail;
-       struct lline *next_lost;
+       /* Accumulated and coalesced lost lines */
+       struct lline *lost;
+       int lenlost;
+       struct plost plost;
        char *bol;
        int len;
        /* bit 0 up to (N-1) are on if the parent has this line (i.e.
@@ -95,34 +108,6 @@ struct sline {
        unsigned long *p_lno;
 };
 
-static char *grab_blob(const unsigned char *sha1, unsigned int mode,
-                      unsigned long *size, struct userdiff_driver *textconv,
-                      const char *path)
-{
-       char *blob;
-       enum object_type type;
-
-       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 if (textconv) {
-               struct diff_filespec *df = alloc_filespec(path);
-               fill_filespec(df, sha1, 1, mode);
-               *size = fill_textconv(textconv, df, &blob);
-               free_filespec(df);
-       } else {
-               blob = read_sha1_file(sha1, &type, size);
-               if (type != OBJ_BLOB)
-                       die("object '%s' is not a blob!", sha1_to_hex(sha1));
-       }
-       return blob;
-}
-
 static int match_string_spaces(const char *line1, int len1,
                               const char *line2, int len2,
                               long flags)
@@ -163,36 +148,180 @@ static int match_string_spaces(const char *line1, int len1,
        return 0;
 }
 
-static void append_lost(struct sline *sline, int n, const char *line, int len, long flags)
+enum coalesce_direction { MATCH, BASE, NEW };
+
+/* Coalesce new lines into base by finding LCS */
+static struct lline *coalesce_lines(struct lline *base, int *lenbase,
+                                   struct lline *new, int lennew,
+                                   unsigned long parent, long flags)
 {
-       struct lline *lline;
-       unsigned long this_mask = (1UL<<n);
-       if (line[len-1] == '\n')
-               len--;
+       int **lcs;
+       enum coalesce_direction **directions;
+       struct lline *baseend, *newend = NULL;
+       int i, j, origbaselen = *lenbase;
 
-       /* Check to see if we can squash things */
-       if (sline->lost_head) {
-               lline = sline->next_lost;
-               while (lline) {
-                       if (match_string_spaces(lline->line, lline->len,
-                                               line, len, flags)) {
-                               lline->parent_map |= this_mask;
-                               sline->next_lost = lline->next;
-                               return;
+       if (new == NULL)
+               return base;
+
+       if (base == NULL) {
+               *lenbase = lennew;
+               return new;
+       }
+
+       /*
+        * Coalesce new lines into base by finding the LCS
+        * - Create the table to run dynamic programming
+        * - Compute the LCS
+        * - Then reverse read the direction structure:
+        *   - If we have MATCH, assign parent to base flag, and consume
+        *   both baseend and newend
+        *   - Else if we have BASE, consume baseend
+        *   - Else if we have NEW, insert newend lline into base and
+        *   consume newend
+        */
+       lcs = xcalloc(origbaselen + 1, sizeof(int*));
+       directions = xcalloc(origbaselen + 1, sizeof(enum coalesce_direction*));
+       for (i = 0; i < origbaselen + 1; i++) {
+               lcs[i] = xcalloc(lennew + 1, sizeof(int));
+               directions[i] = xcalloc(lennew + 1, sizeof(enum coalesce_direction));
+               directions[i][0] = BASE;
+       }
+       for (j = 1; j < lennew + 1; j++)
+               directions[0][j] = NEW;
+
+       for (i = 1, baseend = base; i < origbaselen + 1; i++) {
+               for (j = 1, newend = new; j < lennew + 1; j++) {
+                       if (match_string_spaces(baseend->line, baseend->len,
+                                               newend->line, newend->len, flags)) {
+                               lcs[i][j] = lcs[i - 1][j - 1] + 1;
+                               directions[i][j] = MATCH;
+                       } else if (lcs[i][j - 1] >= lcs[i - 1][j]) {
+                               lcs[i][j] = lcs[i][j - 1];
+                               directions[i][j] = NEW;
+                       } else {
+                               lcs[i][j] = lcs[i - 1][j];
+                               directions[i][j] = BASE;
                        }
-                       lline = lline->next;
+                       if (newend->next)
+                               newend = newend->next;
                }
+               if (baseend->next)
+                       baseend = baseend->next;
+       }
+
+       for (i = 0; i < origbaselen + 1; i++)
+               free(lcs[i]);
+       free(lcs);
+
+       /* At this point, baseend and newend point to the end of each lists */
+       i--;
+       j--;
+       while (i != 0 || j != 0) {
+               if (directions[i][j] == MATCH) {
+                       baseend->parent_map |= 1<<parent;
+                       baseend = baseend->prev;
+                       newend = newend->prev;
+                       i--;
+                       j--;
+               } else if (directions[i][j] == NEW) {
+                       struct lline *lline;
+
+                       lline = newend;
+                       /* Remove lline from new list and update newend */
+                       if (lline->prev)
+                               lline->prev->next = lline->next;
+                       else
+                               new = lline->next;
+                       if (lline->next)
+                               lline->next->prev = lline->prev;
+
+                       newend = lline->prev;
+                       j--;
+
+                       /* Add lline to base list */
+                       if (baseend) {
+                               lline->next = baseend->next;
+                               lline->prev = baseend;
+                               if (lline->prev)
+                                       lline->prev->next = lline;
+                       }
+                       else {
+                               lline->next = base;
+                               base = lline;
+                       }
+                       (*lenbase)++;
+
+                       if (lline->next)
+                               lline->next->prev = lline;
+
+               } else {
+                       baseend = baseend->prev;
+                       i--;
+               }
+       }
+
+       newend = new;
+       while (newend) {
+               struct lline *lline = newend;
+               newend = newend->next;
+               free(lline);
+       }
+
+       for (i = 0; i < origbaselen + 1; i++)
+               free(directions[i]);
+       free(directions);
+
+       return base;
+}
+
+static char *grab_blob(const unsigned char *sha1, unsigned int mode,
+                      unsigned long *size, struct userdiff_driver *textconv,
+                      const char *path)
+{
+       char *blob;
+       enum object_type type;
+
+       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 if (textconv) {
+               struct diff_filespec *df = alloc_filespec(path);
+               fill_filespec(df, sha1, 1, mode);
+               *size = fill_textconv(textconv, df, &blob);
+               free_filespec(df);
+       } else {
+               blob = read_sha1_file(sha1, &type, size);
+               if (type != OBJ_BLOB)
+                       die("object '%s' is not a blob!", sha1_to_hex(sha1));
        }
+       return blob;
+}
+
+static void append_lost(struct sline *sline, int n, const char *line, int len)
+{
+       struct lline *lline;
+       unsigned long this_mask = (1UL<<n);
+       if (line[len-1] == '\n')
+               len--;
 
        lline = xmalloc(sizeof(*lline) + len + 1);
        lline->len = len;
        lline->next = NULL;
+       lline->prev = sline->plost.lost_tail;
+       if (lline->prev)
+               lline->prev->next = lline;
+       else
+               sline->plost.lost_head = lline;
+       sline->plost.lost_tail = lline;
+       sline->plost.len++;
        lline->parent_map = this_mask;
        memcpy(lline->line, line, len);
        lline->line[len] = 0;
-       *sline->lost_tail = lline;
-       sline->lost_tail = &lline->next;
-       sline->next_lost = NULL;
 }
 
 struct combine_diff_state {
@@ -203,7 +332,6 @@ struct combine_diff_state {
        int n;
        struct sline *sline;
        struct sline *lost_bucket;
-       long flags;
 };
 
 static void consume_line(void *state_, char *line, unsigned long len)
@@ -236,14 +364,13 @@ static void consume_line(void *state_, char *line, unsigned long len)
                                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)
                return; /* not in any hunk yet */
        switch (line[0]) {
        case '-':
-               append_lost(state->lost_bucket, state->n, line+1, len-1, state->flags);
+               append_lost(state->lost_bucket, state->n, line+1, len-1);
                break;
        case '+':
                state->sline[state->lno-1].flag |= state->nmask;
@@ -276,7 +403,6 @@ static void combine_diff(const unsigned char *parent, unsigned int mode,
        xpp.flags = flags;
        memset(&xecfg, 0, sizeof(xecfg));
        memset(&state, 0, sizeof(state));
-       state.flags = flags;
        state.nmask = nmask;
        state.sline = sline;
        state.lno = 1;
@@ -298,8 +424,18 @@ static void combine_diff(const unsigned char *parent, unsigned int mode,
                struct lline *ll;
                sline[lno].p_lno[n] = p_lno;
 
+               /* Coalesce new lines */
+               if (sline[lno].plost.lost_head) {
+                       struct sline *sl = &sline[lno];
+                       sl->lost = coalesce_lines(sl->lost, &sl->lenlost,
+                                                 sl->plost.lost_head,
+                                                 sl->plost.len, n, flags);
+                       sl->plost.lost_head = sl->plost.lost_tail = NULL;
+                       sl->plost.len = 0;
+               }
+
                /* How many lines would this sline advance the p_lno? */
-               ll = sline[lno].lost_head;
+               ll = sline[lno].lost;
                while (ll) {
                        if (ll->parent_map & nmask)
                                p_lno++; /* '-' means parent had it */
@@ -319,7 +455,7 @@ static int interesting(struct sline *sline, unsigned long all_mask)
        /* If some parents lost lines here, or if we have added to
         * some parent, it is interesting.
         */
-       return ((sline->flag & all_mask) || sline->lost_head);
+       return ((sline->flag & all_mask) || sline->lost);
 }
 
 static unsigned long adjust_hunk_tail(struct sline *sline,
@@ -387,8 +523,11 @@ static int give_context(struct sline *sline, unsigned long cnt, int num_parent)
                unsigned long k;
 
                /* Paint a few lines before the first interesting line. */
-               while (j < i)
-                       sline[j++].flag |= mark | no_pre_delete;
+               while (j < i) {
+                       if (!(sline[j].flag & mark))
+                               sline[j].flag |= no_pre_delete;
+                       sline[j++].flag |= mark;
+               }
 
        again:
                /* we know up to i is to be included.  where does the
@@ -502,7 +641,7 @@ static int make_hunks(struct sline *sline, unsigned long cnt,
                has_interesting = 0;
                for (j = i; j < hunk_end && !has_interesting; j++) {
                        unsigned long this_diff = sline[j].flag & all_mask;
-                       struct lline *ll = sline[j].lost_head;
+                       struct lline *ll = sline[j].lost;
                        if (this_diff) {
                                /* This has some changes.  Is it the
                                 * same as others?
@@ -656,7 +795,7 @@ static void dump_sline(struct sline *sline, const char *line_prefix,
                        int j;
                        unsigned long p_mask;
                        struct sline *sl = &sline[lno++];
-                       ll = (sl->flag & no_pre_delete) ? NULL : sl->lost_head;
+                       ll = (sl->flag & no_pre_delete) ? NULL : sl->lost;
                        while (ll) {
                                printf("%s%s", line_prefix, c_old);
                                for (j = 0; j < num_parent; j++) {
@@ -707,7 +846,7 @@ static void reuse_combine_diff(struct sline *sline, unsigned long cnt,
        jmask = (1UL<<j);
 
        for (lno = 0; lno <= cnt; lno++) {
-               struct lline *ll = sline->lost_head;
+               struct lline *ll = sline->lost;
                sline->p_lno[i] = sline->p_lno[j];
                while (ll) {
                        if (ll->parent_map & jmask)
@@ -966,10 +1105,6 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 
        sline = xcalloc(cnt+2, sizeof(*sline));
        sline[0].bol = result;
-       for (lno = 0; lno <= cnt + 1; lno++) {
-               sline[lno].lost_tail = &sline[lno].lost_head;
-               sline[lno].flag = 0;
-       }
        for (lno = 0, cp = result; cp < result + result_size; cp++) {
                if (*cp == '\n') {
                        sline[lno].len = cp - sline[lno].bol;
@@ -1019,8 +1154,8 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
        free(result);
 
        for (lno = 0; lno < cnt; lno++) {
-               if (sline[lno].lost_head) {
-                       struct lline *ll = sline[lno].lost_head;
+               if (sline[lno].lost) {
+                       struct lline *ll = sline[lno].lost;
                        while (ll) {
                                struct lline *tmp = ll;
                                ll = ll->next;
@@ -1088,8 +1223,6 @@ void show_combined_diff(struct combine_diff_path *p,
 {
        struct diff_options *opt = &rev->diffopt;
 
-       if (!p->len)
-               return;
        if (opt->output_format & (DIFF_FORMAT_RAW |
                                  DIFF_FORMAT_NAME |
                                  DIFF_FORMAT_NAME_STATUS))
@@ -1153,17 +1286,66 @@ static void handle_combined_callback(struct diff_options *opt,
        q.queue = xcalloc(num_paths, sizeof(struct diff_filepair *));
        q.alloc = num_paths;
        q.nr = num_paths;
-       for (i = 0, p = paths; p; p = p->next) {
-               if (!p->len)
-                       continue;
+       for (i = 0, p = paths; p; p = p->next)
                q.queue[i++] = combined_pair(p, num_parent);
-       }
        opt->format_callback(&q, opt, opt->format_callback_data);
        for (i = 0; i < num_paths; i++)
                free_combined_pair(q.queue[i]);
        free(q.queue);
 }
 
+static const char *path_path(void *obj)
+{
+       struct combine_diff_path *path = (struct combine_diff_path *)obj;
+
+       return path->path;
+}
+
+
+/* find set of paths that every parent touches */
+static struct combine_diff_path *find_paths(const unsigned char *sha1,
+       const struct sha1_array *parents, struct diff_options *opt)
+{
+       struct combine_diff_path *paths = NULL;
+       int i, num_parent = parents->nr;
+
+       int output_format = opt->output_format;
+       const char *orderfile = opt->orderfile;
+
+       opt->output_format = DIFF_FORMAT_NO_OUTPUT;
+       /* tell diff_tree to emit paths in sorted (=tree) order */
+       opt->orderfile = NULL;
+
+       for (i = 0; i < num_parent; i++) {
+               /*
+                * show stat against the first parent even when doing
+                * combined diff.
+                */
+               int stat_opt = (output_format &
+                               (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT));
+               if (i == 0 && stat_opt)
+                       opt->output_format = stat_opt;
+               else
+                       opt->output_format = DIFF_FORMAT_NO_OUTPUT;
+               diff_tree_sha1(parents->sha1[i], sha1, "", opt);
+               diffcore_std(opt);
+               paths = intersect_paths(paths, i, num_parent);
+
+               /* if showing diff, show it in requested order */
+               if (opt->output_format != DIFF_FORMAT_NO_OUTPUT &&
+                   orderfile) {
+                       diffcore_order(orderfile);
+               }
+
+               diff_flush(opt);
+       }
+
+       opt->output_format = output_format;
+       opt->orderfile = orderfile;
+       return paths;
+}
+
+
 void diff_tree_combined(const unsigned char *sha1,
                        const struct sha1_array *parents,
                        int dense,
@@ -1171,54 +1353,66 @@ void diff_tree_combined(const unsigned char *sha1,
 {
        struct diff_options *opt = &rev->diffopt;
        struct diff_options diffopts;
-       struct combine_diff_path *p, *paths = NULL;
+       struct combine_diff_path *p, *paths;
        int i, num_paths, needsep, show_log_first, num_parent = parents->nr;
 
-       diffopts = *opt;
-       diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
-       DIFF_OPT_SET(&diffopts, RECURSIVE);
-       DIFF_OPT_CLR(&diffopts, ALLOW_EXTERNAL);
+       /* nothing to do, if no parents */
+       if (!num_parent)
+               return;
 
        show_log_first = !!rev->loginfo && !rev->no_commit_id;
        needsep = 0;
-       /* find set of paths that everybody touches */
-       for (i = 0; i < num_parent; i++) {
-               /* show stat against the first parent even
-                * when doing combined diff.
-                */
-               int stat_opt = (opt->output_format &
-                               (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT));
-               if (i == 0 && stat_opt)
-                       diffopts.output_format = stat_opt;
-               else
-                       diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
-               diff_tree_sha1(parents->sha1[i], sha1, "", &diffopts);
-               diffcore_std(&diffopts);
-               paths = intersect_paths(paths, i, num_parent);
+       if (show_log_first) {
+               show_log(rev);
 
-               if (show_log_first && i == 0) {
-                       show_log(rev);
+               if (rev->verbose_header && opt->output_format)
+                       printf("%s%c", diff_line_prefix(opt),
+                              opt->line_termination);
+       }
 
-                       if (rev->verbose_header && opt->output_format)
-                               printf("%s%c", diff_line_prefix(opt),
-                                      opt->line_termination);
+       diffopts = *opt;
+       copy_pathspec(&diffopts.pathspec, &opt->pathspec);
+       DIFF_OPT_SET(&diffopts, RECURSIVE);
+       DIFF_OPT_CLR(&diffopts, ALLOW_EXTERNAL);
+
+       /* find set of paths that everybody touches
+        *
+        * NOTE find_paths() also handles --stat, as it computes
+        * diff(sha1,parent_i) for all i to do the job, specifically
+        * for parent0.
+        */
+       paths = find_paths(sha1, parents, &diffopts);
+
+       /* find out number of surviving paths */
+       for (num_paths = 0, p = paths; p; p = p->next)
+               num_paths++;
+
+       /* order paths according to diffcore_order */
+       if (opt->orderfile && num_paths) {
+               struct obj_order *o;
+
+               o = xmalloc(sizeof(*o) * num_paths);
+               for (i = 0, p = paths; p; p = p->next, i++)
+                       o[i].obj = p;
+               order_objects(opt->orderfile, path_path, o, num_paths);
+               for (i = 0; i < num_paths - 1; i++) {
+                       p = o[i].obj;
+                       p->next = o[i+1].obj;
                }
-               diff_flush(&diffopts);
-       }
 
-       /* find out surviving paths */
-       for (num_paths = 0, p = paths; p; p = p->next) {
-               if (p->len)
-                       num_paths++;
+               p = o[num_paths-1].obj;
+               p->next = NULL;
+               paths = o[0].obj;
+               free(o);
        }
+
+
        if (num_paths) {
                if (opt->output_format & (DIFF_FORMAT_RAW |
                                          DIFF_FORMAT_NAME |
                                          DIFF_FORMAT_NAME_STATUS)) {
-                       for (p = paths; p; p = p->next) {
-                               if (p->len)
-                                       show_raw_diff(p, num_parent, rev);
-                       }
+                       for (p = paths; p; p = p->next)
+                               show_raw_diff(p, num_parent, rev);
                        needsep = 1;
                }
                else if (opt->output_format &
@@ -1231,11 +1425,9 @@ void diff_tree_combined(const unsigned char *sha1,
                        if (needsep)
                                printf("%s%c", diff_line_prefix(opt),
                                       opt->line_termination);
-                       for (p = paths; p; p = p->next) {
-                               if (p->len)
-                                       show_patch_diff(p, num_parent, dense,
-                                                       0, rev);
-                       }
+                       for (p = paths; p; p = p->next)
+                               show_patch_diff(p, num_parent, dense,
+                                               0, rev);
                }
        }
 
@@ -1245,12 +1437,14 @@ void diff_tree_combined(const unsigned char *sha1,
                paths = paths->next;
                free(tmp);
        }
+
+       free_pathspec(&diffopts.pathspec);
 }
 
 void diff_tree_combined_merge(const struct commit *commit, int dense,
                              struct rev_info *rev)
 {
-       struct commit_list *parent = commit->parents;
+       struct commit_list *parent = get_saved_parents(rev, commit);
        struct sha1_array parents = SHA1_ARRAY_INIT;
 
        while (parent) {