ui-log: Implement support for commit graphs

Teach CGit to print an ASCII art commit graph to the left of the commit
message, similar to 'git log --graph'. The graph adds extra lines (table
rows) to the log when needed to add/remove/shuffle edges in the graph.

When 'showmsg' is enabled, the graph is automatically padded to account
for the extra lines added by the commit message/notes.

This feature is controlled by a new config variable: "enable-commit-graph"
(disabled by default), and individual repos can control it by setting
"repo.enable-commit-graph".

Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/cgit.c b/cgit.c
index 412fbf0..53ab68d 100644
--- a/cgit.c
+++ b/cgit.c
@@ -1,239 +1,243 @@
 /* cgit.c: cgi for the git scm
  *
  * Copyright (C) 2006 Lars Hjemli
  * Copyright (C) 2010 Jason A. Donenfeld <Jason@zx2c4.com>
  *
  * Licensed under GNU General Public License v2
  *   (see COPYING for full license text)
  */
 
 #include "cgit.h"
 #include "cache.h"
 #include "cmd.h"
 #include "configfile.h"
 #include "html.h"
 #include "ui-shared.h"
 #include "ui-stats.h"
 #include "scan-tree.h"
 
 const char *cgit_version = CGIT_VERSION;
 
 void add_mimetype(const char *name, const char *value)
 {
         struct string_list_item *item;
 
         item = string_list_insert(&ctx.cfg.mimetypes, xstrdup(name));
         item->util = xstrdup(value);
 }
 
 struct cgit_filter *new_filter(const char *cmd, int extra_args)
 {
         struct cgit_filter *f;
 
         if (!cmd || !cmd[0])
                 return NULL;
 
         f = xmalloc(sizeof(struct cgit_filter));
         f->cmd = xstrdup(cmd);
         f->argv = xmalloc((2 + extra_args) * sizeof(char *));
         f->argv[0] = f->cmd;
         f->argv[1] = NULL;
         return f;
 }
 
 static void process_cached_repolist(const char *path);
 
 void repo_config(struct cgit_repo *repo, const char *name, const char *value)
 {
         if (!strcmp(name, "name"))
                 repo->name = xstrdup(value);
         else if (!strcmp(name, "clone-url"))
                 repo->clone_url = xstrdup(value);
         else if (!strcmp(name, "desc"))
                 repo->desc = xstrdup(value);
         else if (!strcmp(name, "owner"))
                 repo->owner = xstrdup(value);
         else if (!strcmp(name, "defbranch"))
                 repo->defbranch = xstrdup(value);
         else if (!strcmp(name, "snapshots"))
                 repo->snapshots = ctx.cfg.snapshots & cgit_parse_snapshots_mask(value);
+        else if (!strcmp(name, "enable-commit-graph"))
+                repo->enable_commit_graph = ctx.cfg.enable_commit_graph * atoi(value);
         else if (!strcmp(name, "enable-log-filecount"))
                 repo->enable_log_filecount = ctx.cfg.enable_log_filecount * atoi(value);
         else if (!strcmp(name, "enable-log-linecount"))
                 repo->enable_log_linecount = ctx.cfg.enable_log_linecount * atoi(value);
         else if (!strcmp(name, "enable-remote-branches"))
                 repo->enable_remote_branches = atoi(value);
         else if (!strcmp(name, "enable-subject-links"))
                 repo->enable_subject_links = atoi(value);
         else if (!strcmp(name, "max-stats"))
                 repo->max_stats = cgit_find_stats_period(value, NULL);
         else if (!strcmp(name, "module-link"))
                 repo->module_link= xstrdup(value);
         else if (!strcmp(name, "section"))
                 repo->section = xstrdup(value);
         else if (!strcmp(name, "readme") && value != NULL) {
                 repo->readme = xstrdup(value);
         } else if (ctx.cfg.enable_filter_overrides) {
                 if (!strcmp(name, "about-filter"))
                         repo->about_filter = new_filter(value, 0);
                 else if (!strcmp(name, "commit-filter"))
                         repo->commit_filter = new_filter(value, 0);
                 else if (!strcmp(name, "source-filter"))
                         repo->source_filter = new_filter(value, 1);
         }
 }
 
 void config_cb(const char *name, const char *value)
 {
         if (!strcmp(name, "section") || !strcmp(name, "repo.group"))
                 ctx.cfg.section = xstrdup(value);
         else if (!strcmp(name, "repo.url"))
                 ctx.repo = cgit_add_repo(value);
         else if (ctx.repo && !strcmp(name, "repo.path"))
                 ctx.repo->path = trim_end(value, '/');
         else if (ctx.repo && !prefixcmp(name, "repo."))
                 repo_config(ctx.repo, name + 5, value);
         else if (!strcmp(name, "readme"))
                 ctx.cfg.readme = xstrdup(value);
         else if (!strcmp(name, "root-title"))
                 ctx.cfg.root_title = xstrdup(value);
         else if (!strcmp(name, "root-desc"))
                 ctx.cfg.root_desc = xstrdup(value);
         else if (!strcmp(name, "root-readme"))
                 ctx.cfg.root_readme = xstrdup(value);
         else if (!strcmp(name, "css"))
                 ctx.cfg.css = xstrdup(value);
         else if (!strcmp(name, "favicon"))
                 ctx.cfg.favicon = xstrdup(value);
         else if (!strcmp(name, "footer"))
                 ctx.cfg.footer = xstrdup(value);
         else if (!strcmp(name, "head-include"))
                 ctx.cfg.head_include = xstrdup(value);
         else if (!strcmp(name, "header"))
                 ctx.cfg.header = xstrdup(value);
         else if (!strcmp(name, "logo"))
                 ctx.cfg.logo = xstrdup(value);
         else if (!strcmp(name, "index-header"))
                 ctx.cfg.index_header = xstrdup(value);
         else if (!strcmp(name, "index-info"))
                 ctx.cfg.index_info = xstrdup(value);
         else if (!strcmp(name, "logo-link"))
                 ctx.cfg.logo_link = xstrdup(value);
         else if (!strcmp(name, "module-link"))
                 ctx.cfg.module_link = xstrdup(value);
         else if (!strcmp(name, "strict-export"))
                 ctx.cfg.strict_export = xstrdup(value);
         else if (!strcmp(name, "virtual-root")) {
                 ctx.cfg.virtual_root = trim_end(value, '/');
                 if (!ctx.cfg.virtual_root && (!strcmp(value, "/")))
                         ctx.cfg.virtual_root = "";
         } else if (!strcmp(name, "nocache"))
                 ctx.cfg.nocache = atoi(value);
         else if (!strcmp(name, "noplainemail"))
                 ctx.cfg.noplainemail = atoi(value);
         else if (!strcmp(name, "noheader"))
                 ctx.cfg.noheader = atoi(value);
         else if (!strcmp(name, "snapshots"))
                 ctx.cfg.snapshots = cgit_parse_snapshots_mask(value);
         else if (!strcmp(name, "enable-filter-overrides"))
                 ctx.cfg.enable_filter_overrides = atoi(value);
         else if (!strcmp(name, "enable-gitweb-owner"))
                 ctx.cfg.enable_gitweb_owner = atoi(value);
         else if (!strcmp(name, "enable-index-links"))
                 ctx.cfg.enable_index_links = atoi(value);
+        else if (!strcmp(name, "enable-commit-graph"))
+                ctx.cfg.enable_commit_graph = atoi(value);
         else if (!strcmp(name, "enable-log-filecount"))
                 ctx.cfg.enable_log_filecount = atoi(value);
         else if (!strcmp(name, "enable-log-linecount"))
                 ctx.cfg.enable_log_linecount = atoi(value);
         else if (!strcmp(name, "enable-remote-branches"))
                 ctx.cfg.enable_remote_branches = atoi(value);
         else if (!strcmp(name, "enable-subject-links"))
                 ctx.cfg.enable_subject_links = atoi(value);
         else if (!strcmp(name, "enable-tree-linenumbers"))
                 ctx.cfg.enable_tree_linenumbers = atoi(value);
         else if (!strcmp(name, "max-stats"))
                 ctx.cfg.max_stats = cgit_find_stats_period(value, NULL);
         else if (!strcmp(name, "cache-size"))
                 ctx.cfg.cache_size = atoi(value);
         else if (!strcmp(name, "cache-root"))
                 ctx.cfg.cache_root = xstrdup(expand_macros(value));
         else if (!strcmp(name, "cache-root-ttl"))
                 ctx.cfg.cache_root_ttl = atoi(value);
         else if (!strcmp(name, "cache-repo-ttl"))
                 ctx.cfg.cache_repo_ttl = atoi(value);
         else if (!strcmp(name, "cache-scanrc-ttl"))
                 ctx.cfg.cache_scanrc_ttl = atoi(value);
         else if (!strcmp(name, "cache-static-ttl"))
                 ctx.cfg.cache_static_ttl = atoi(value);
         else if (!strcmp(name, "cache-dynamic-ttl"))
                 ctx.cfg.cache_dynamic_ttl = atoi(value);
         else if (!strcmp(name, "about-filter"))
                 ctx.cfg.about_filter = new_filter(value, 0);
         else if (!strcmp(name, "commit-filter"))
                 ctx.cfg.commit_filter = new_filter(value, 0);
         else if (!strcmp(name, "embedded"))
                 ctx.cfg.embedded = atoi(value);
         else if (!strcmp(name, "max-atom-items"))
                 ctx.cfg.max_atom_items = atoi(value);
         else if (!strcmp(name, "max-message-length"))
                 ctx.cfg.max_msg_len = atoi(value);
         else if (!strcmp(name, "max-repodesc-length"))
                 ctx.cfg.max_repodesc_len = atoi(value);
         else if (!strcmp(name, "max-blob-size"))
                 ctx.cfg.max_blob_size = atoi(value);
         else if (!strcmp(name, "max-repo-count"))
                 ctx.cfg.max_repo_count = atoi(value);
         else if (!strcmp(name, "max-commit-count"))
                 ctx.cfg.max_commit_count = atoi(value);
         else if (!strcmp(name, "project-list"))
                 ctx.cfg.project_list = xstrdup(expand_macros(value));
         else if (!strcmp(name, "scan-path"))
                 if (!ctx.cfg.nocache && ctx.cfg.cache_size)
                         process_cached_repolist(expand_macros(value));
                 else if (ctx.cfg.project_list)
                         scan_projects(expand_macros(value),
                                       ctx.cfg.project_list, repo_config);
                 else
                         scan_tree(expand_macros(value), repo_config);
         else if (!strcmp(name, "section-from-path"))
                 ctx.cfg.section_from_path = atoi(value);
         else if (!strcmp(name, "source-filter"))
                 ctx.cfg.source_filter = new_filter(value, 1);
         else if (!strcmp(name, "summary-log"))
                 ctx.cfg.summary_log = atoi(value);
         else if (!strcmp(name, "summary-branches"))
                 ctx.cfg.summary_branches = atoi(value);
         else if (!strcmp(name, "summary-tags"))
                 ctx.cfg.summary_tags = atoi(value);
         else if (!strcmp(name, "side-by-side-diffs"))
                 ctx.cfg.ssdiff = atoi(value);
         else if (!strcmp(name, "agefile"))
                 ctx.cfg.agefile = xstrdup(value);
         else if (!strcmp(name, "renamelimit"))
                 ctx.cfg.renamelimit = atoi(value);
         else if (!strcmp(name, "remove-suffix"))
                 ctx.cfg.remove_suffix = atoi(value);
         else if (!strcmp(name, "robots"))
                 ctx.cfg.robots = xstrdup(value);
         else if (!strcmp(name, "clone-prefix"))
                 ctx.cfg.clone_prefix = xstrdup(value);
         else if (!strcmp(name, "local-time"))
                 ctx.cfg.local_time = atoi(value);
         else if (!prefixcmp(name, "mimetype."))
                 add_mimetype(name + 9, value);
         else if (!strcmp(name, "include"))
                 parse_configfile(expand_macros(value), config_cb);
 }
 
 static void querystring_cb(const char *name, const char *value)
 {
         if (!value)
                 value = "";
 
         if (!strcmp(name,"r")) {
                 ctx.qry.repo = xstrdup(value);
                 ctx.repo = cgit_get_repoinfo(value);
         } else if (!strcmp(name, "p")) {
                 ctx.qry.page = xstrdup(value);
         } else if (!strcmp(name, "url")) {
                 if (*value == '/')
@@ -447,192 +451,194 @@ static void process_request(void *cbdata)
                 ctx->page.title = "cgit error";
                 cgit_print_http_headers(ctx);
                 cgit_print_docstart(ctx);
                 cgit_print_pageheader(ctx);
                 cgit_print_error("Invalid request");
                 cgit_print_docend();
                 return;
         }
 
         /* If cmd->want_vpath is set, assume ctx->qry.path contains a "virtual"
          * in-project path limit to be made available at ctx->qry.vpath.
          * Otherwise, no path limit is in effect (ctx->qry.vpath = NULL).
          */
         ctx->qry.vpath = cmd->want_vpath ? ctx->qry.path : NULL;
 
         if (cmd->want_repo && !ctx->repo) {
                 cgit_print_http_headers(ctx);
                 cgit_print_docstart(ctx);
                 cgit_print_pageheader(ctx);
                 cgit_print_error(fmt("No repository selected"));
                 cgit_print_docend();
                 return;
         }
 
         if (ctx->repo && prepare_repo_cmd(ctx))
                 return;
 
         if (cmd->want_layout) {
                 cgit_print_http_headers(ctx);
                 cgit_print_docstart(ctx);
                 cgit_print_pageheader(ctx);
         }
 
         cmd->fn(ctx);
 
         if (cmd->want_layout)
                 cgit_print_docend();
 }
 
 int cmp_repos(const void *a, const void *b)
 {
         const struct cgit_repo *ra = a, *rb = b;
         return strcmp(ra->url, rb->url);
 }
 
 char *build_snapshot_setting(int bitmap)
 {
         const struct cgit_snapshot_format *f;
         char *result = xstrdup("");
         char *tmp;
         int len;
 
         for (f = cgit_snapshot_formats; f->suffix; f++) {
                 if (f->bit & bitmap) {
                         tmp = result;
                         result = xstrdup(fmt("%s%s ", tmp, f->suffix));
                         free(tmp);
                 }
         }
         len = strlen(result);
         if (len)
                 result[len - 1] = '\0';
         return result;
 }
 
 char *get_first_line(char *txt)
 {
         char *t = xstrdup(txt);
         char *p = strchr(t, '\n');
         if (p)
                 *p = '\0';
         return t;
 }
 
 void print_repo(FILE *f, struct cgit_repo *repo)
 {
         fprintf(f, "repo.url=%s\n", repo->url);
         fprintf(f, "repo.name=%s\n", repo->name);
         fprintf(f, "repo.path=%s\n", repo->path);
         if (repo->owner)
                 fprintf(f, "repo.owner=%s\n", repo->owner);
         if (repo->desc) {
                 char *tmp = get_first_line(repo->desc);
                 fprintf(f, "repo.desc=%s\n", tmp);
                 free(tmp);
         }
         if (repo->readme)
                 fprintf(f, "repo.readme=%s\n", repo->readme);
         if (repo->defbranch)
                 fprintf(f, "repo.defbranch=%s\n", repo->defbranch);
         if (repo->module_link)
                 fprintf(f, "repo.module-link=%s\n", repo->module_link);
         if (repo->section)
                 fprintf(f, "repo.section=%s\n", repo->section);
         if (repo->clone_url)
                 fprintf(f, "repo.clone-url=%s\n", repo->clone_url);
+        fprintf(f, "repo.enable-commit-graph=%d\n",
+                repo->enable_commit_graph);
         fprintf(f, "repo.enable-log-filecount=%d\n",
                 repo->enable_log_filecount);
         fprintf(f, "repo.enable-log-linecount=%d\n",
                 repo->enable_log_linecount);
         if (repo->about_filter && repo->about_filter != ctx.cfg.about_filter)
                 fprintf(f, "repo.about-filter=%s\n", repo->about_filter->cmd);
         if (repo->commit_filter && repo->commit_filter != ctx.cfg.commit_filter)
                 fprintf(f, "repo.commit-filter=%s\n", repo->commit_filter->cmd);
         if (repo->source_filter && repo->source_filter != ctx.cfg.source_filter)
                 fprintf(f, "repo.source-filter=%s\n", repo->source_filter->cmd);
         if (repo->snapshots != ctx.cfg.snapshots) {
                 char *tmp = build_snapshot_setting(repo->snapshots);
                 fprintf(f, "repo.snapshots=%s\n", tmp);
                 free(tmp);
         }
         if (repo->max_stats != ctx.cfg.max_stats)
                 fprintf(f, "repo.max-stats=%s\n",
                         cgit_find_stats_periodname(repo->max_stats));
         fprintf(f, "\n");
 }
 
 void print_repolist(FILE *f, struct cgit_repolist *list, int start)
 {
         int i;
 
         for(i = start; i < list->count; i++)
                 print_repo(f, &list->repos[i]);
 }
 
 /* Scan 'path' for git repositories, save the resulting repolist in 'cached_rc'
  * and return 0 on success.
  */
 static int generate_cached_repolist(const char *path, const char *cached_rc)
 {
         char *locked_rc;
         int idx;
         FILE *f;
 
         locked_rc = xstrdup(fmt("%s.lock", cached_rc));
         f = fopen(locked_rc, "wx");
         if (!f) {
                 /* Inform about the error unless the lockfile already existed,
                  * since that only means we've got concurrent requests.
                  */
                 if (errno != EEXIST)
                         fprintf(stderr, "[cgit] Error opening %s: %s (%d)\n",
                                 locked_rc, strerror(errno), errno);
                 return errno;
         }
         idx = cgit_repolist.count;
         if (ctx.cfg.project_list)
                 scan_projects(path, ctx.cfg.project_list, repo_config);
         else
                 scan_tree(path, repo_config);
         print_repolist(f, &cgit_repolist, idx);
         if (rename(locked_rc, cached_rc))
                 fprintf(stderr, "[cgit] Error renaming %s to %s: %s (%d)\n",
                         locked_rc, cached_rc, strerror(errno), errno);
         fclose(f);
         return 0;
 }
 
 static void process_cached_repolist(const char *path)
 {
         struct stat st;
         char *cached_rc;
         time_t age;
         unsigned long hash;
 
         hash = hash_str(path);
         if (ctx.cfg.project_list)
                 hash += hash_str(ctx.cfg.project_list);
         cached_rc = xstrdup(fmt("%s/rc-%8lx", ctx.cfg.cache_root, hash));
 
         if (stat(cached_rc, &st)) {
                 /* Nothing is cached, we need to scan without forking. And
                  * if we fail to generate a cached repolist, we need to
                  * invoke scan_tree manually.
                  */
                 if (generate_cached_repolist(path, cached_rc)) {
                         if (ctx.cfg.project_list)
                                 scan_projects(path, ctx.cfg.project_list,
                                               repo_config);
                         else
                                 scan_tree(path, repo_config);
                 }
                 return;
         }
 
         parse_configfile(cached_rc, config_cb);
 
         /* If the cached configfile hasn't expired, lets exit now */
         age = time(NULL) - st.st_mtime;
         if (age <= (ctx.cfg.cache_scanrc_ttl * 60))
                 return;