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, 14 insertions, 1 deletions

diff --git a/cgitrc.5.txt b/cgitrc.5.txt
index 75b6584..b45c46b 100644
--- a/cgitrc.5.txt
+++ b/cgitrc.5.txt
@@ -1,189 +1,194 @@
 :man source:   cgit
 :man manual:   cgit
 
 CGITRC(5)
 ========
 
 
 NAME
 ----
 cgitrc - runtime configuration for cgit
 
 
 SYNOPSIS
 --------
 Cgitrc contains all runtime settings for cgit, including the list of git
 repositories, formatted as a line-separated list of NAME=VALUE pairs. Blank
 lines, and lines starting with '#', are ignored.
 
 
 LOCATION
 --------
 The default location of cgitrc, defined at compile time, is /etc/cgitrc. At
 runtime, cgit will consult the environment variable CGIT_CONFIG and, if
 defined, use its value instead.
 
 
 GLOBAL SETTINGS
 ---------------
 about-filter::
         Specifies a command which will be invoked to format the content of
         about pages (both top-level and for each repository). The command will
         get the content of the about-file on its STDIN, and the STDOUT from the
         command will be included verbatim on the about page. Default value:
         none.
 
 agefile::
         Specifies a path, relative to each repository path, which can be used
         to specify the date and time of the youngest commit in the repository.
         The first line in the file is used as input to the "parse_date"
         function in libgit. Recommended timestamp-format is "yyyy-mm-dd
         hh:mm:ss". Default value: "info/web/last-modified".
 
 cache-root::
         Path used to store the cgit cache entries. Default value:
         "/var/cache/cgit".
 
 cache-dynamic-ttl::
         Number which specifies the time-to-live, in minutes, for the cached
         version of repository pages accessed without a fixed SHA1. Default
         value: "5".
 
 cache-repo-ttl::
         Number which specifies the time-to-live, in minutes, for the cached
         version of the repository summary page. Default value: "5".
 
 cache-root-ttl::
         Number which specifies the time-to-live, in minutes, for the cached
         version of the repository index page. Default value: "5".
 
 cache-scanrc-ttl::
         Number which specifies the time-to-live, in minutes, for the result
         of scanning a path for git repositories. Default value: "15".
 
 cache-size::
         The maximum number of entries in the cgit cache. Default value: "0"
         (i.e. caching is disabled).
 
 cache-static-ttl::
         Number which specifies the time-to-live, in minutes, for the cached
         version of repository pages accessed with a fixed SHA1. Default value:
         "5".
 
 clone-prefix::
         Space-separated list of common prefixes which, when combined with a
         repository url, generates valid clone urls for the repository. This
         setting is only used if `repo.clone-url` is unspecified. Default value:
         none.
 
 commit-filter::
         Specifies a command which will be invoked to format commit messages.
         The command will get the message on its STDIN, and the STDOUT from the
         command will be included verbatim as the commit message, i.e. this can
         be used to implement bugtracker integration. Default value: none.
 
 css::
         Url which specifies the css document to include in all cgit pages.
         Default value: "/cgit.css".
 
 embedded::
         Flag which, when set to "1", will make cgit generate a html fragment
         suitable for embedding in other html pages. Default value: none. See
         also: "noheader".
-        
+
+enable-commit-graph::
+        Flag which, when set to "1", will make cgit print an ASCII-art commit
+        history graph to the left of the commit messages in the repository
+        log page. Default value: "0".
+
 enable-filter-overrides::
         Flag which, when set to "1", allows all filter settings to be
         overridden in repository-specific cgitrc files. Default value: none.
 
 enable-gitweb-owner::
         If set to "1" and scan-path is enabled, we first check each repository
         for the git config value "gitweb.owner" to determine the owner.
         Default value: "1". See also: scan-path.
 
 enable-index-links::
         Flag which, when set to "1", will make cgit generate extra links for
         each repo in the repository index (specifically, to the "summary",
         "commit" and "tree" pages). Default value: "0".
 
 enable-log-filecount::
         Flag which, when set to "1", will make cgit print the number of
         modified files for each commit on the repository log page. Default
         value: "0".
 
 enable-log-linecount::
         Flag which, when set to "1", will make cgit print the number of added
         and removed lines for each commit on the repository log page. Default
         value: "0".
 
 enable-remote-branches::
         Flag which, when set to "1", will make cgit display remote branches
         in the summary and refs views. Default value: "0". See also:
         "repo.enable-remote-branches".
 
 enable-subject-links::
         Flag which, when set to "1", will make cgit use the subject of the
         parent commit as link text when generating links to parent commits
         in commit view. Default value: "0". See also:
         "repo.enable-subject-links".
 
 enable-tree-linenumbers::
         Flag which, when set to "1", will make cgit generate linenumber links
         for plaintext blobs printed in the tree view. Default value: "1".
 
 favicon::
         Url used as link to a shortcut icon for cgit. If specified, it is
         suggested to use the value "/favicon.ico" since certain browsers will
         ignore other values. Default value: none.
 
 footer::
         The content of the file specified with this option will be included
         verbatim at the bottom of all pages (i.e. it replaces the standard
         "generated by..." message. Default value: none.
 
 head-include::
         The content of the file specified with this option will be included
         verbatim in the html HEAD section on all pages. Default value: none.
 
 header::
         The content of the file specified with this option will be included
         verbatim at the top of all pages. Default value: none.
 
 include::
         Name of a configfile to include before the rest of the current config-
         file is parsed. Default value: none.
 
 index-header::
         The content of the file specified with this option will be included
         verbatim above the repository index. This setting is deprecated, and
         will not be supported by cgit-1.0 (use root-readme instead). Default
         value: none.
 
 index-info::
         The content of the file specified with this option will be included
         verbatim below the heading on the repository index page. This setting
         is deprecated, and will not be supported by cgit-1.0 (use root-desc
         instead). Default value: none.
 
 local-time::
         Flag which, if set to "1", makes cgit print commit and tag times in the
         servers timezone. Default value: "0".
 
 logo::
         Url which specifies the source of an image which will be used as a logo
         on all cgit pages. Default value: "/cgit.png".
 
 logo-link::
         Url loaded when clicking on the cgit logo image. If unspecified the
         calculated url of the repository index page will be used. Default
         value: none.
 
 max-atom-items::
         Specifies the number of items to display in atom feeds view. Default
         value: "10".
 
 max-commit-count::
         Specifies the number of entries to list per page in "log" view. Default
         value: "50".
 
 max-message-length::
         Specifies the maximum number of commit message characters to display in
@@ -261,279 +266,287 @@ root-desc::
         value: "a fast webinterface for the git dscm".
 
 root-readme::
         The content of the file specified with this option will be included
         verbatim below the "about" link on the repository index page. Default
         value: none.
 
 root-title::
         Text printed as heading on the repository index page. Default value:
         "Git Repository Browser".
 
 scan-path::
         A path which will be scanned for repositories. If caching is enabled,
         the result will be cached as a cgitrc include-file in the cache
         directory. If project-list has been defined prior to scan-path,
         scan-path loads only the directories listed in the file pointed to by
         project-list. Default value: none. See also: cache-scanrc-ttl,
         project-list.
 
 section::
         The name of the current repository section - all repositories defined
         after this option will inherit the current section name. Default value:
         none.
 
 section-from-path::
         A number which, if specified before scan-path, specifies how many
         path elements from each repo path to use as a default section name.
         If negative, cgit will discard the specified number of path elements
         above the repo directory. Default value: 0.
 
 side-by-side-diffs::
         If set to "1" shows side-by-side diffs instead of unidiffs per
         default. Default value: "0".
 
 snapshots::
         Text which specifies the default set of snapshot formats generated by
         cgit. The value is a space-separated list of zero or more of the
         values "tar", "tar.gz", "tar.bz2" and "zip". Default value: none.
 
 source-filter::
         Specifies a command which will be invoked to format plaintext blobs
         in the tree view. The command will get the blob content on its STDIN
         and the name of the blob as its only command line argument. The STDOUT
         from the command will be included verbatim as the blob contents, i.e.
         this can be used to implement e.g. syntax highlighting. Default value:
         none.
 
 summary-branches::
         Specifies the number of branches to display in the repository "summary"
         view. Default value: "10".
 
 summary-log::
         Specifies the number of log entries to display in the repository
         "summary" view. Default value: "10".
 
 summary-tags::
         Specifies the number of tags to display in the repository "summary"
         view. Default value: "10".
 
 strict-export::
         Filename which, if specified, needs to be present within the repository
         for cgit to allow access to that repository. This can be used to emulate
         gitweb's EXPORT_OK and STRICT_EXPORT functionality and limit cgit's
         repositories to match those exported by git-daemon. This option MUST come
         before 'scan-path'.
 
 virtual-root::
         Url which, if specified, will be used as root for all cgit links. It
         will also cause cgit to generate 'virtual urls', i.e. urls like
         '/cgit/tree/README' as opposed to '?r=cgit&p=tree&path=README'. Default
         value: none.
         NOTE: cgit has recently learned how to use PATH_INFO to achieve the
         same kind of virtual urls, so this option will probably be deprecated.
 
 REPOSITORY SETTINGS
 -------------------
 repo.about-filter::
         Override the default about-filter. Default value: none. See also:
         "enable-filter-overrides".
 
 repo.clone-url::
         A list of space-separated urls which can be used to clone this repo.
         Default value: none.
 
 repo.commit-filter::
         Override the default commit-filter. Default value: none. See also:
         "enable-filter-overrides".
 
 repo.defbranch::
         The name of the default branch for this repository. If no such branch
         exists in the repository, the first branch name (when sorted) is used
         as default instead. Default value: "master".
 
 repo.desc::
         The value to show as repository description. Default value: none.
 
+repo.enable-commit-graph::
+        A flag which can be used to disable the global setting
+        `enable-commit-graph'. Default value: none.
+
 repo.enable-log-filecount::
         A flag which can be used to disable the global setting
         `enable-log-filecount'. Default value: none.
 
 repo.enable-log-linecount::
         A flag which can be used to disable the global setting
         `enable-log-linecount'. Default value: none.
 
 repo.enable-remote-branches::
         Flag which, when set to "1", will make cgit display remote branches
         in the summary and refs views. Default value: <enable-remote-branches>.
 
 repo.enable-subject-links::
         A flag which can be used to override the global setting
         `enable-subject-links'. Default value: none.
 
 repo.max-stats::
         Override the default maximum statistics period. Valid values are equal
         to the values specified for the global "max-stats" setting. Default
         value: none.
 
 repo.name::
         The value to show as repository name. Default value: <repo.url>.
 
 repo.owner::
         A value used to identify the owner of the repository. Default value:
         none.
 
 repo.path::
         An absolute path to the repository directory. For non-bare repositories
         this is the .git-directory. Default value: none.
 
 repo.readme::
         A path (relative to <repo.path>) which specifies a file to include
         verbatim as the "About" page for this repo. You may also specify a
         git refspec by head or by hash by prepending the refspec followed by
         a colon. For example, "master:docs/readme.mkd" Default value: <readme>.
 
 repo.snapshots::
         A mask of allowed snapshot-formats for this repo, restricted by the
         "snapshots" global setting. Default value: <snapshots>.
 
 repo.section::
         Override the current section name for this repository. Default value:
         none.
 
 repo.source-filter::
         Override the default source-filter. Default value: none. See also:
         "enable-filter-overrides".
 
 repo.url::
         The relative url used to access the repository. This must be the first
         setting specified for each repo. Default value: none.
 
 
 REPOSITORY-SPECIFIC CGITRC FILE
 -------------------------------
 When the option "scan-path" is used to auto-discover git repositories, cgit
 will try to parse the file "cgitrc" within any found repository. Such a
 repo-specific config file may contain any of the repo-specific options
 described above, except "repo.url" and "repo.path". Additionally, the "filter"
 options are only acknowledged in repo-specific config files when
 "enable-filter-overrides" is set to "1".
 
 Note: the "repo." prefix is dropped from the option names in repo-specific
 config files, e.g. "repo.desc" becomes "desc".
 
 
 EXAMPLE CGITRC FILE
 -------------------
 
 ....
 # Enable caching of up to 1000 output entriess
 cache-size=1000
 
 
 # Specify some default clone prefixes
 clone-prefix=git://foobar.com ssh://foobar.com/pub/git http://foobar.com/git
 
 # Specify the css url
 css=/css/cgit.css
 
 
 # Show extra links for each repository on the index page
 enable-index-links=1
 
 
+# Enable ASCII art commit history graph on the log pages
+enable-commit-graph=1
+
+
 # Show number of affected files per commit on the log pages
 enable-log-filecount=1
 
 
 # Show number of added/removed lines per commit on the log pages
 enable-log-linecount=1
 
 
 # Add a cgit favicon
 favicon=/favicon.ico
 
 
 # Use a custom logo
 logo=/img/mylogo.png
 
 
 # Enable statistics per week, month and quarter
 max-stats=quarter
 
 
 # Set the title and heading of the repository index page
 root-title=foobar.com git repositories
 
 
 # Set a subheading for the repository index page
 root-desc=tracking the foobar development
 
 
 # Include some more info about foobar.com on the index page
 root-readme=/var/www/htdocs/about.html
 
 
 # Allow download of tar.gz, tar.bz2 and zip-files
 snapshots=tar.gz tar.bz2 zip
 
 
 ##
 ## List of common mimetypes
 ##
 
 mimetype.gif=image/gif
 mimetype.html=text/html
 mimetype.jpg=image/jpeg
 mimetype.jpeg=image/jpeg
 mimetype.pdf=application/pdf
 mimetype.png=image/png
 mimetype.svg=image/svg+xml
 
 
 ##
 ## List of repositories.
 ## PS: Any repositories listed when section is unset will not be
 ##     displayed under a section heading
 ## PPS: This list could be kept in a different file (e.g. '/etc/cgitrepos')
 ##      and included like this:
 ##        include=/etc/cgitrepos
 ##
 
 
 repo.url=foo
 repo.path=/pub/git/foo.git
 repo.desc=the master foo repository
 repo.owner=fooman@foobar.com
 repo.readme=info/web/about.html
 
 
 repo.url=bar
 repo.path=/pub/git/bar.git
 repo.desc=the bars for your foo
 repo.owner=barman@foobar.com
 repo.readme=info/web/about.html
 
 
 # The next repositories will be displayed under the 'extras' heading
 section=extras
 
 
 repo.url=baz
 repo.path=/pub/git/baz.git
 repo.desc=a set of extensions for bar users
 
 repo.url=wiz
 repo.path=/pub/git/wiz.git
 repo.desc=the wizard of foo
 
 
 # Add some mirrored repositories
 section=mirrors
 
 
 repo.url=git
 repo.path=/pub/git/git.git
 repo.desc=the dscm
 
 
 repo.url=linux