[PATCH] Modify git-rev-list to linearise the commit history in merge order.

[thirdparty/git.git] / Documentation / git-rev-list.txt

diff --git a/Documentation/git-rev-list.txt b/Documentation/git-rev-list.txt
index f2c5fa9f4cd598681ccdb6873f98fee5d37e845b..3cfa58b5bd8a19884b0395a97c1e370e8008b903 100644 (file)
--- a/Documentation/git-rev-list.txt
+++ b/Documentation/git-rev-list.txt
@@ -9,7 +9,7 @@ git-rev-list - Lists commit objects in reverse chronological order
 
 SYNOPSIS
 --------
-'git-rev-list' <commit>
+'git-rev-list' [ *--max-count*=number ] [ *--max-age*=timestamp ] [ *--min-age*=timestamp ] [ *--merge-order* [ *--show-breaks* ] ] <commit>
 
 DESCRIPTION
 -----------
@@ -17,11 +17,39 @@ Lists commit objects in reverse chronological order starting at the
 given commit, taking ancestry relationship into account.  This is
 useful to produce human-readable log output.
 
+If *--merge-order* is specified, the commit history is decomposed into a unique sequence of minimal, non-linear
+epochs and maximal, linear epochs. Non-linear epochs are then linearised by sorting them into merge order, which 
+is described below.
+
+Maximal, linear epochs correspond to periods of sequential development. Minimal, non-linear epochs 
+correspond to periods of divergent development followed by a converging merge. The theory of epochs is described
+in more detail at link:http://blackcubes.dyndns.org/epoch/[http://blackcubes.dyndns.org/epoch/].
+
+The merge order for a non-linear epoch is defined as a linearisation for which the following invariants are true:
+
+    1. if a commit P is reachable from commit N, commit P sorts after commit N in the linearised list.
+    2. if Pi and Pj are any two parents of a merge M (with i < j), then any commit N, such that N is reachable from Pj
+       but not reachable from Pi, sorts before all commits reachable from Pi.
+   
+Invariant 1 states that later commits appear before earlier commits they are derived from.
+
+Invariant 2 states that commits unique to "later" parents in a merge, appear before all commits from "earlier" parents of
+a merge.
+
+If *--show-breaks* is specified, each item of the list is output with a 2-character prefix consisting of one of: 
+ (|), (^), (=) followed by a space. 
+Commits marked with (=) represent the boundaries of minimal, non-linear epochs and correspond either to the start of a period of divergent development or to the end of such a period. 
+Commits marked with (|) are direct parents of commits immediately preceding the marked commit in the list.
+Commits marked with (^) are not parents of the immediately preceding commit. These "breaks" represent necessary discontinuities implied by trying to represent an arbtirary DAG in a linear form.
+
+*--show-breaks* is only valid if *--merge-order* is also specified.
 
 Author
 ------
 Written by Linus Torvalds <torvalds@osdl.org>
 
+Original *--merge-order* logic by Jon Seymour <jon.seymour@gmail.com>
+
 Documentation
 --------------
 Documentation by David Greaves, Junio C Hamano and the git-list <git@vger.kernel.org>.