| Junio C Hamano | 2db3e75 | 2010-09-03 21:33:06 | [diff] [blame^] | 1 | <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" |
| 2 | "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd"> |
| 3 | <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en"> |
| 4 | <head> |
| 5 | <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> |
| 6 | <meta name="generator" content="AsciiDoc 8.2.5" /> |
| 7 | <style type="text/css"> |
| 8 | /* Debug borders */ |
| 9 | p, li, dt, dd, div, pre, h1, h2, h3, h4, h5, h6 { |
| 10 | /* |
| 11 | border: 1px solid red; |
| 12 | */ |
| 13 | } |
| 14 | |
| 15 | body { |
| 16 | margin: 1em 5% 1em 5%; |
| 17 | } |
| 18 | |
| 19 | a { |
| 20 | color: blue; |
| 21 | text-decoration: underline; |
| 22 | } |
| 23 | a:visited { |
| 24 | color: fuchsia; |
| 25 | } |
| 26 | |
| 27 | em { |
| 28 | font-style: italic; |
| 29 | } |
| 30 | |
| 31 | strong { |
| 32 | font-weight: bold; |
| 33 | } |
| 34 | |
| 35 | tt { |
| 36 | color: navy; |
| 37 | } |
| 38 | |
| 39 | h1, h2, h3, h4, h5, h6 { |
| 40 | color: #527bbd; |
| 41 | font-family: sans-serif; |
| 42 | margin-top: 1.2em; |
| 43 | margin-bottom: 0.5em; |
| 44 | line-height: 1.3; |
| 45 | } |
| 46 | |
| 47 | h1, h2, h3 { |
| 48 | border-bottom: 2px solid silver; |
| 49 | } |
| 50 | h2 { |
| 51 | padding-top: 0.5em; |
| 52 | } |
| 53 | h3 { |
| 54 | float: left; |
| 55 | } |
| 56 | h3 + * { |
| 57 | clear: left; |
| 58 | } |
| 59 | |
| 60 | div.sectionbody { |
| 61 | font-family: serif; |
| 62 | margin-left: 0; |
| 63 | } |
| 64 | |
| 65 | hr { |
| 66 | border: 1px solid silver; |
| 67 | } |
| 68 | |
| 69 | p { |
| 70 | margin-top: 0.5em; |
| 71 | margin-bottom: 0.5em; |
| 72 | } |
| 73 | |
| 74 | pre { |
| 75 | padding: 0; |
| 76 | margin: 0; |
| 77 | } |
| 78 | |
| 79 | span#author { |
| 80 | color: #527bbd; |
| 81 | font-family: sans-serif; |
| 82 | font-weight: bold; |
| 83 | font-size: 1.1em; |
| 84 | } |
| 85 | span#email { |
| 86 | } |
| 87 | span#revision { |
| 88 | font-family: sans-serif; |
| 89 | } |
| 90 | |
| 91 | div#footer { |
| 92 | font-family: sans-serif; |
| 93 | font-size: small; |
| 94 | border-top: 2px solid silver; |
| 95 | padding-top: 0.5em; |
| 96 | margin-top: 4.0em; |
| 97 | } |
| 98 | div#footer-text { |
| 99 | float: left; |
| 100 | padding-bottom: 0.5em; |
| 101 | } |
| 102 | div#footer-badges { |
| 103 | float: right; |
| 104 | padding-bottom: 0.5em; |
| 105 | } |
| 106 | |
| 107 | div#preamble, |
| 108 | div.tableblock, div.imageblock, div.exampleblock, div.verseblock, |
| 109 | div.quoteblock, div.literalblock, div.listingblock, div.sidebarblock, |
| 110 | div.admonitionblock { |
| 111 | margin-right: 10%; |
| 112 | margin-top: 1.5em; |
| 113 | margin-bottom: 1.5em; |
| 114 | } |
| 115 | div.admonitionblock { |
| 116 | margin-top: 2.5em; |
| 117 | margin-bottom: 2.5em; |
| 118 | } |
| 119 | |
| 120 | div.content { /* Block element content. */ |
| 121 | padding: 0; |
| 122 | } |
| 123 | |
| 124 | /* Block element titles. */ |
| 125 | div.title, caption.title { |
| 126 | font-family: sans-serif; |
| 127 | font-weight: bold; |
| 128 | text-align: left; |
| 129 | margin-top: 1.0em; |
| 130 | margin-bottom: 0.5em; |
| 131 | } |
| 132 | div.title + * { |
| 133 | margin-top: 0; |
| 134 | } |
| 135 | |
| 136 | td div.title:first-child { |
| 137 | margin-top: 0.0em; |
| 138 | } |
| 139 | div.content div.title:first-child { |
| 140 | margin-top: 0.0em; |
| 141 | } |
| 142 | div.content + div.title { |
| 143 | margin-top: 0.0em; |
| 144 | } |
| 145 | |
| 146 | div.sidebarblock > div.content { |
| 147 | background: #ffffee; |
| 148 | border: 1px solid silver; |
| 149 | padding: 0.5em; |
| 150 | } |
| 151 | |
| 152 | div.listingblock { |
| 153 | margin-right: 0%; |
| 154 | } |
| 155 | div.listingblock > div.content { |
| 156 | border: 1px solid silver; |
| 157 | background: #f4f4f4; |
| 158 | padding: 0.5em; |
| 159 | } |
| 160 | |
| 161 | div.quoteblock > div.content { |
| 162 | padding-left: 2.0em; |
| 163 | } |
| 164 | |
| 165 | div.attribution { |
| 166 | text-align: right; |
| 167 | } |
| 168 | div.verseblock + div.attribution { |
| 169 | text-align: left; |
| 170 | } |
| 171 | |
| 172 | div.admonitionblock .icon { |
| 173 | vertical-align: top; |
| 174 | font-size: 1.1em; |
| 175 | font-weight: bold; |
| 176 | text-decoration: underline; |
| 177 | color: #527bbd; |
| 178 | padding-right: 0.5em; |
| 179 | } |
| 180 | div.admonitionblock td.content { |
| 181 | padding-left: 0.5em; |
| 182 | border-left: 2px solid silver; |
| 183 | } |
| 184 | |
| 185 | div.exampleblock > div.content { |
| 186 | border-left: 2px solid silver; |
| 187 | padding: 0.5em; |
| 188 | } |
| 189 | |
| 190 | div.verseblock div.content { |
| 191 | white-space: pre; |
| 192 | } |
| 193 | |
| 194 | div.imageblock div.content { padding-left: 0; } |
| 195 | div.imageblock img { border: 1px solid silver; } |
| 196 | span.image img { border-style: none; } |
| 197 | |
| 198 | dl { |
| 199 | margin-top: 0.8em; |
| 200 | margin-bottom: 0.8em; |
| 201 | } |
| 202 | dt { |
| 203 | margin-top: 0.5em; |
| 204 | margin-bottom: 0; |
| 205 | font-style: italic; |
| 206 | } |
| 207 | dd > *:first-child { |
| 208 | margin-top: 0; |
| 209 | } |
| 210 | |
| 211 | ul, ol { |
| 212 | list-style-position: outside; |
| 213 | } |
| 214 | div.olist2 ol { |
| 215 | list-style-type: lower-alpha; |
| 216 | } |
| 217 | |
| 218 | div.tableblock > table { |
| 219 | border: 3px solid #527bbd; |
| 220 | } |
| 221 | thead { |
| 222 | font-family: sans-serif; |
| 223 | font-weight: bold; |
| 224 | } |
| 225 | tfoot { |
| 226 | font-weight: bold; |
| 227 | } |
| 228 | |
| 229 | div.hlist { |
| 230 | margin-top: 0.8em; |
| 231 | margin-bottom: 0.8em; |
| 232 | } |
| 233 | div.hlist td { |
| 234 | padding-bottom: 5px; |
| 235 | } |
| 236 | td.hlist1 { |
| 237 | vertical-align: top; |
| 238 | font-style: italic; |
| 239 | padding-right: 0.8em; |
| 240 | } |
| 241 | td.hlist2 { |
| 242 | vertical-align: top; |
| 243 | } |
| 244 | |
| 245 | @media print { |
| 246 | div#footer-badges { display: none; } |
| 247 | } |
| 248 | |
| 249 | div#toctitle { |
| 250 | color: #527bbd; |
| 251 | font-family: sans-serif; |
| 252 | font-size: 1.1em; |
| 253 | font-weight: bold; |
| 254 | margin-top: 1.0em; |
| 255 | margin-bottom: 0.1em; |
| 256 | } |
| 257 | |
| 258 | div.toclevel1, div.toclevel2, div.toclevel3, div.toclevel4 { |
| 259 | margin-top: 0; |
| 260 | margin-bottom: 0; |
| 261 | } |
| 262 | div.toclevel2 { |
| 263 | margin-left: 2em; |
| 264 | font-size: 0.9em; |
| 265 | } |
| 266 | div.toclevel3 { |
| 267 | margin-left: 4em; |
| 268 | font-size: 0.9em; |
| 269 | } |
| 270 | div.toclevel4 { |
| 271 | margin-left: 6em; |
| 272 | font-size: 0.9em; |
| 273 | } |
| 274 | /* Workarounds for IE6's broken and incomplete CSS2. */ |
| 275 | |
| 276 | div.sidebar-content { |
| 277 | background: #ffffee; |
| 278 | border: 1px solid silver; |
| 279 | padding: 0.5em; |
| 280 | } |
| 281 | div.sidebar-title, div.image-title { |
| 282 | font-family: sans-serif; |
| 283 | font-weight: bold; |
| 284 | margin-top: 0.0em; |
| 285 | margin-bottom: 0.5em; |
| 286 | } |
| 287 | |
| 288 | div.listingblock div.content { |
| 289 | border: 1px solid silver; |
| 290 | background: #f4f4f4; |
| 291 | padding: 0.5em; |
| 292 | } |
| 293 | |
| 294 | div.quoteblock-content { |
| 295 | padding-left: 2.0em; |
| 296 | } |
| 297 | |
| 298 | div.exampleblock-content { |
| 299 | border-left: 2px solid silver; |
| 300 | padding-left: 0.5em; |
| 301 | } |
| 302 | |
| 303 | /* IE6 sets dynamically generated links as visited. */ |
| 304 | div#toc a:visited { color: blue; } |
| 305 | </style> |
| 306 | <title>merge API</title> |
| 307 | </head> |
| 308 | <body> |
| 309 | <div id="header"> |
| 310 | <h1>merge API</h1> |
| 311 | </div> |
| 312 | <div id="preamble"> |
| 313 | <div class="sectionbody"> |
| 314 | <div class="para"><p>The merge API helps a program to reconcile two competing sets of |
| 315 | improvements to some files (e.g., unregistered changes from the work |
| 316 | tree versus changes involved in switching to a new branch), reporting |
| 317 | conflicts if found. The library called through this API is |
| 318 | responsible for a few things.</p></div> |
| 319 | <div class="ilist"><ul> |
| 320 | <li> |
| 321 | <p> |
| 322 | determining which trees to merge (recursive ancestor consolidation); |
| 323 | </p> |
| 324 | </li> |
| 325 | <li> |
| 326 | <p> |
| 327 | lining up corresponding files in the trees to be merged (rename |
| 328 | detection, subtree shifting), reporting edge cases like add/add |
| 329 | and rename/rename conflicts to the user; |
| 330 | </p> |
| 331 | </li> |
| 332 | <li> |
| 333 | <p> |
| 334 | performing a three-way merge of corresponding files, taking |
| 335 | path-specific merge drivers (specified in <tt>.gitattributes</tt>) |
| 336 | into account. |
| 337 | </p> |
| 338 | </li> |
| 339 | </ul></div> |
| 340 | </div> |
| 341 | </div> |
| 342 | <h2 id="_low_level_single_file_merge">Low-level (single file) merge</h2> |
| 343 | <div class="sectionbody"> |
| 344 | <div class="vlist"><dl> |
| 345 | <dt> |
| 346 | <tt>ll_merge</tt> |
| 347 | </dt> |
| 348 | <dd> |
| 349 | <p> |
| 350 | Perform a three-way single-file merge in core. This is |
| 351 | a thin wrapper around <tt>xdl_merge</tt> that takes the path and |
| 352 | any merge backend specified in <tt>.gitattributes</tt> or |
| 353 | <tt>.git/info/attributes</tt> into account. Returns 0 for a |
| 354 | clean merge. |
| 355 | </p> |
| 356 | </dd> |
| 357 | </dl></div> |
| 358 | <div class="para"><p>The caller:</p></div> |
| 359 | <div class="olist"><ol> |
| 360 | <li> |
| 361 | <p> |
| 362 | allocates an mmbuffer_t variable for the result; |
| 363 | </p> |
| 364 | </li> |
| 365 | <li> |
| 366 | <p> |
| 367 | allocates and fills variables with the file's original content |
| 368 | and two modified versions (using <tt>read_mmfile</tt>, for example); |
| 369 | </p> |
| 370 | </li> |
| 371 | <li> |
| 372 | <p> |
| 373 | calls ll_merge(); |
| 374 | </p> |
| 375 | </li> |
| 376 | <li> |
| 377 | <p> |
| 378 | reads the output from result_buf.ptr and result_buf.size; |
| 379 | </p> |
| 380 | </li> |
| 381 | <li> |
| 382 | <p> |
| 383 | releases buffers when finished (free(ancestor.ptr); free(ours.ptr); |
| 384 | free(theirs.ptr); free(result_buf.ptr);). |
| 385 | </p> |
| 386 | </li> |
| 387 | </ol></div> |
| 388 | <div class="para"><p>If the modifications do not merge cleanly, <tt>ll_merge</tt> will return a |
| 389 | nonzero value and <tt>result_buf</tt> will generally include a description of |
| 390 | the conflict bracketed by markers such as the traditional <tt><<<<<<<</tt> |
| 391 | and <tt>>>>>>>></tt>.</p></div> |
| 392 | <div class="para"><p>The <tt>ancestor_label</tt>, <tt>our_label</tt>, and <tt>their_label</tt> parameters are |
| 393 | used to label the different sides of a conflict if the merge driver |
| 394 | supports this.</p></div> |
| 395 | <div class="para"><p>The <tt>flag</tt> parameter is a bitfield:</p></div> |
| 396 | <div class="ilist"><ul> |
| 397 | <li> |
| 398 | <p> |
| 399 | The <tt>LL_OPT_VIRTUAL_ANCESTOR</tt> bit indicates whether this is an |
| 400 | internal merge to consolidate ancestors for a recursive merge. |
| 401 | </p> |
| 402 | </li> |
| 403 | <li> |
| 404 | <p> |
| 405 | The <tt>LL_OPT_FAVOR_MASK</tt> bits allow local conflicts to be automatically |
| 406 | resolved in favor of one side or the other (as in <em>git merge-file</em> |
| 407 | <tt>—ours</tt>/<tt>—theirs</tt>/<tt>—union</tt>). |
| 408 | They can be populated by <tt>create_ll_flag</tt>, whose argument can be |
| 409 | <tt>XDL_MERGE_FAVOR_OURS</tt>, <tt>XDL_MERGE_FAVOR_THEIRS</tt>, or |
| 410 | <tt>XDL_MERGE_FAVOR_UNION</tt>. |
| 411 | </p> |
| 412 | </li> |
| 413 | </ul></div> |
| 414 | </div> |
| 415 | <h2 id="_everything_else">Everything else</h2> |
| 416 | <div class="sectionbody"> |
| 417 | <div class="para"><p>Talk about <merge-recursive.h> and merge_file():</p></div> |
| 418 | <div class="ilist"><ul> |
| 419 | <li> |
| 420 | <p> |
| 421 | merge_trees() to merge with rename detection |
| 422 | </p> |
| 423 | </li> |
| 424 | <li> |
| 425 | <p> |
| 426 | merge_recursive() for ancestor consolidation |
| 427 | </p> |
| 428 | </li> |
| 429 | <li> |
| 430 | <p> |
| 431 | try_merge_command() for other strategies |
| 432 | </p> |
| 433 | </li> |
| 434 | <li> |
| 435 | <p> |
| 436 | conflict format |
| 437 | </p> |
| 438 | </li> |
| 439 | <li> |
| 440 | <p> |
| 441 | merge options |
| 442 | </p> |
| 443 | </li> |
| 444 | </ul></div> |
| 445 | <div class="para"><p>(Daniel, Miklos, Stephan, JC)</p></div> |
| 446 | </div> |
| 447 | <div id="footer"> |
| 448 | <div id="footer-text"> |
| 449 | Last updated 2010-09-03 21:30:46 UTC |
| 450 | </div> |
| 451 | </div> |
| 452 | </body> |
| 453 | </html> |
