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margin-bottom: 0; } div.toclevel2 { margin-left: 2em; font-size: 0.9em; } div.toclevel3 { margin-left: 4em; font-size: 0.9em; } div.toclevel4 { margin-left: 6em; font-size: 0.9em; } /* Workarounds for IE6's broken and incomplete CSS2. */ div.sidebar-content { background: #ffffee; border: 1px solid silver; padding: 0.5em; } div.sidebar-title, div.image-title { color: #527bbd; font-family: sans-serif; font-weight: bold; margin-top: 0.0em; margin-bottom: 0.5em; } div.listingblock div.content { border: 1px solid silver; background: #f4f4f4; padding: 0.5em; } div.quoteblock-attribution { padding-top: 0.5em; text-align: right; } div.verseblock-content { white-space: pre; } div.verseblock-attribution { padding-top: 0.75em; text-align: left; } div.exampleblock-content { border-left: 2px solid silver; padding-left: 0.5em; } /* IE6 sets dynamically generated links as visited. */ div#toc a:visited { color: blue; } </style> </head> <body> <div id="header"> <h1>merge API</h1> </div> <div id="preamble"> <div class="sectionbody"> <div class="paragraph"><p>The merge API helps a program to reconcile two competing sets of improvements to some files (e.g., unregistered changes from the work tree versus changes involved in switching to a new branch), reporting conflicts if found. The library called through this API is responsible for a few things.</p></div> <div class="ulist"><ul> <li> <p> determining which trees to merge (recursive ancestor consolidation); </p> </li> <li> <p> lining up corresponding files in the trees to be merged (rename detection, subtree shifting), reporting edge cases like add/add and rename/rename conflicts to the user; </p> </li> <li> <p> performing a three-way merge of corresponding files, taking path-specific merge drivers (specified in <tt>.gitattributes</tt>) into account. </p> </li> </ul></div> </div> </div> <h2 id="_data_structures">Data structures</h2> <div class="sectionbody"> <div class="ulist"><ul> <li> <p> <tt>mmbuffer_t</tt>, <tt>mmfile_t</tt> </p> </li> </ul></div> <div class="paragraph"><p>These store data usable for use by the xdiff backend, for writing and for reading, respectively. See <tt>xdiff/xdiff.h</tt> for the definitions and <tt>diff.c</tt> for examples.</p></div> <div class="ulist"><ul> <li> <p> <tt>struct ll_merge_options</tt> </p> </li> </ul></div> <div class="paragraph"><p>This describes the set of options the calling program wants to affect the operation of a low-level (single file) merge. Some options:</p></div> <div class="dlist"><dl> <dt class="hdlist1"> <tt>virtual_ancestor</tt> </dt> <dd> <p> Behave as though this were part of a merge between common ancestors in a recursive merge. If a helper program is specified by the <tt>[merge "<driver>"] recursive</tt> configuration, it will be used (see <a href="gitattributes.html">gitattributes(5)</a>). </p> </dd> <dt class="hdlist1"> <tt>variant</tt> </dt> <dd> <p> Resolve local conflicts automatically in favor of one side or the other (as in <em>git merge-file</em> <tt>--ours</tt>/<tt>--theirs</tt>/<tt>--union</tt>). Can be <tt>0</tt>, <tt>XDL_MERGE_FAVOR_OURS</tt>, <tt>XDL_MERGE_FAVOR_THEIRS</tt>, or <tt>XDL_MERGE_FAVOR_UNION</tt>. </p> </dd> <dt class="hdlist1"> <tt>renormalize</tt> </dt> <dd> <p> Resmudge and clean the "base", "theirs" and "ours" files before merging. Use this when the merge is likely to have overlapped with a change in smudge/clean or end-of-line normalization rules. </p> </dd> </dl></div> </div> <h2 id="_low_level_single_file_merge">Low-level (single file) merge</h2> <div class="sectionbody"> <div class="dlist"><dl> <dt class="hdlist1"> <tt>ll_merge</tt> </dt> <dd> <p> Perform a three-way single-file merge in core. This is a thin wrapper around <tt>xdl_merge</tt> that takes the path and any merge backend specified in <tt>.gitattributes</tt> or <tt>.git/info/attributes</tt> into account. Returns 0 for a clean merge. </p> </dd> </dl></div> <div class="paragraph"><p>Calling sequence:</p></div> <div class="ulist"><ul> <li> <p> Prepare a <tt>struct ll_merge_options</tt> to record options. If you have no special requests, skip this and pass <tt>NULL</tt> as the <tt>opts</tt> parameter to use the default options. </p> </li> <li> <p> Allocate an mmbuffer_t variable for the result. </p> </li> <li> <p> Allocate and fill variables with the file’s original content and two modified versions (using <tt>read_mmfile</tt>, for example). </p> </li> <li> <p> Call <tt>ll_merge()</tt>. </p> </li> <li> <p> Read the merged content from <tt>result_buf.ptr</tt> and <tt>result_buf.size</tt>. </p> </li> <li> <p> Release buffers when finished. A simple <tt>free(ancestor.ptr); free(ours.ptr); free(theirs.ptr); free(result_buf.ptr);</tt> will do. </p> </li> </ul></div> <div class="paragraph"><p>If the modifications do not merge cleanly, <tt>ll_merge</tt> will return a nonzero value and <tt>result_buf</tt> will generally include a description of the conflict bracketed by markers such as the traditional <tt><<<<<<<</tt> and <tt>>>>>>>></tt>.</p></div> <div class="paragraph"><p>The <tt>ancestor_label</tt>, <tt>our_label</tt>, and <tt>their_label</tt> parameters are used to label the different sides of a conflict if the merge driver supports this.</p></div> </div> <h2 id="_everything_else">Everything else</h2> <div class="sectionbody"> <div class="paragraph"><p>Talk about <merge-recursive.h> and merge_file():</p></div> <div class="ulist"><ul> <li> <p> merge_trees() to merge with rename detection </p> </li> <li> <p> merge_recursive() for ancestor consolidation </p> </li> <li> <p> try_merge_command() for other strategies </p> </li> <li> <p> conflict format </p> </li> <li> <p> merge options </p> </li> </ul></div> <div class="paragraph"><p>(Daniel, Miklos, Stephan, JC)</p></div> </div> <div id="footer"> <div id="footer-text"> Last updated 2011-01-06 00:29:02 UTC </div> </div> </body> </html>