00001 /** 00002 * @copyright 00003 * ==================================================================== 00004 * Copyright (c) 2000-2004 CollabNet. All rights reserved. 00005 * 00006 * This software is licensed as described in the file COPYING, which 00007 * you should have received as part of this distribution. The terms 00008 * are also available at http://subversion.tigris.org/license-1.html. 00009 * If newer versions of this license are posted there, you may use a 00010 * newer version instead, at your option. 00011 * 00012 * This software consists of voluntary contributions made by many 00013 * individuals. For exact contribution history, see the revision 00014 * history and logs, available at http://subversion.tigris.org/. 00015 * ==================================================================== 00016 * @endcopyright 00017 * 00018 * @file svn_delta.h 00019 * @brief Delta-parsing 00020 */ 00021 00022 /* ==================================================================== */ 00023 00024 00025 00026 #ifndef SVN_DELTA_H 00027 #define SVN_DELTA_H 00028 00029 #include <apr.h> 00030 #include <apr_pools.h> 00031 00032 #include "svn_types.h" 00033 #include "svn_string.h" 00034 #include "svn_error.h" 00035 #include "svn_io.h" 00036 #include "svn_version.h" 00037 00038 #ifdef __cplusplus 00039 extern "C" { 00040 #endif /* __cplusplus */ 00041 00042 00043 00044 /** 00045 * @since New in 1.1. 00046 * 00047 * Get libsvn_delta version information. 00048 */ 00049 const svn_version_t *svn_delta_version (void); 00050 00051 00052 /** Text deltas. 00053 * 00054 * A text delta represents the difference between two strings of 00055 * bytes, the `source' string and the `target' string. Given a source 00056 * string and a target string, we can compute a text delta; given a 00057 * source string and a delta, we can reconstruct the target string. 00058 * However, note that deltas are not reversible: you cannot always 00059 * reconstruct the source string given the target string and delta. 00060 * 00061 * Since text deltas can be very large, the interface here allows us 00062 * to produce and consume them in pieces. Each piece, represented by 00063 * an @c svn_txdelta_window_t structure, describes how to produce the 00064 * next section of the target string. 00065 * 00066 * To compute a new text delta: 00067 * 00068 * - We call @c svn_txdelta on the streams we want to compare. That 00069 * returns us an @c svn_txdelta_stream_t object. 00070 * 00071 * - We then call @c svn_txdelta_next_window on the stream object 00072 * repeatedly. Each call returns a new @c svn_txdelta_window_t 00073 * object, which describes the next portion of the target string. 00074 * When @c svn_txdelta_next_window returns zero, we are done building 00075 * the target string. 00076 * 00077 * @defgroup svn_delta_txt_delta text deltas 00078 * @{ 00079 */ 00080 00081 00082 enum svn_delta_action { 00083 /** Append the @a len bytes at @a offset in the source view to the 00084 * target. 00085 * 00086 * It must be the case that @a 0 <= @a offset < @a offset + 00087 * @a len <= size of source view. 00088 */ 00089 svn_txdelta_source, 00090 00091 /** Append the @a len bytes at @a offset in the target view, to the 00092 * target. 00093 * 00094 * It must be the case that @a 0 <= @a offset < current position in the 00095 * target view. 00096 * 00097 * However! @a offset + @a len may be *beyond* the end of the existing 00098 * target data. "Where the heck does the text come from, then?" 00099 * If you start at @a offset, and append @a len bytes one at a time, 00100 * it'll work out --- you're adding new bytes to the end at the 00101 * same rate you're reading them from the middle. Thus, if your 00102 * current target text is "abcdefgh", and you get an @c svn_delta_target 00103 * instruction whose @a offset is @a 6 and whose @a len is @a 7, 00104 * the resulting string is "abcdefghghghghg". This trick is actually 00105 * useful in encoding long runs of consecutive characters, long runs 00106 * of CR/LF pairs, etc. 00107 */ 00108 svn_txdelta_target, 00109 00110 /** Append the @a len bytes at @a offset in the window's @a new string 00111 * to the target. 00112 * 00113 * It must be the case that @a 0 <= @a offset < @a offset + 00114 * @a len <= length of @a new. Windows MUST use new data in ascending 00115 * order with no overlap at the moment; @c svn_txdelta_to_svndiff 00116 * depends on this. 00117 */ 00118 svn_txdelta_new 00119 }; 00120 00121 /** A single text delta instruction. */ 00122 typedef struct svn_txdelta_op_t 00123 { 00124 enum svn_delta_action action_code; 00125 apr_size_t offset; 00126 apr_size_t length; 00127 } svn_txdelta_op_t; 00128 00129 00130 /** An @c svn_txdelta_window_t object describes how to reconstruct a 00131 * contiguous section of the target string (the "target view") using a 00132 * specified contiguous region of the source string (the "source 00133 * view"). It contains a series of instructions which assemble the 00134 * new target string text by pulling together substrings from: 00135 * 00136 * - the source view, 00137 * 00138 * - the previously constructed portion of the target view, 00139 * 00140 * - a string of new data contained within the window structure 00141 * 00142 * The source view must always slide forward from one window to the 00143 * next; that is, neither the beginning nor the end of the source view 00144 * may move to the left as we read from a window stream. This 00145 * property allows us to apply deltas to non-seekable source streams 00146 * without making a full copy of the source stream. 00147 */ 00148 typedef struct svn_txdelta_window_t 00149 { 00150 00151 /** The offset of the source view for this window. */ 00152 svn_filesize_t sview_offset; 00153 00154 /** The length of the source view for this window. */ 00155 apr_size_t sview_len; 00156 00157 /** The length of the target view for this window, i.e. the number of 00158 * bytes which will be reconstructed by the instruction stream. */ 00159 apr_size_t tview_len; 00160 00161 /** The number of instructions in this window. */ 00162 int num_ops; 00163 00164 /** The number of svn_txdelta_source instructions in this window. If 00165 * this number is 0, we don't need to read the source in order to 00166 * reconstruct the target view. 00167 */ 00168 int src_ops; 00169 00170 /** The instructions for this window. */ 00171 const svn_txdelta_op_t *ops; 00172 00173 /** New data, for use by any `svn_delta_new' instructions. */ 00174 const svn_string_t *new_data; 00175 00176 } svn_txdelta_window_t; 00177 00178 00179 /** A typedef for functions that consume a series of delta windows, for 00180 * use in caller-pushes interfaces. Such functions will typically 00181 * apply the delta windows to produce some file, or save the windows 00182 * somewhere. At the end of the delta window stream, you must call 00183 * this function passing zero for the @a window argument. 00184 */ 00185 typedef svn_error_t * (*svn_txdelta_window_handler_t) 00186 (svn_txdelta_window_t *window, void *baton); 00187 00188 00189 /** A delta stream --- this is the hat from which we pull a series of 00190 * svn_txdelta_window_t objects, which, taken in order, describe the 00191 * entire target string. This type is defined within libsvn_delta, and 00192 * opaque outside that library. 00193 */ 00194 typedef struct svn_txdelta_stream_t svn_txdelta_stream_t; 00195 00196 00197 /** Set @a *window to a pointer to the next window from the delta stream 00198 * @a stream. When we have completely reconstructed the target string, 00199 * set @a *window to zero. 00200 * 00201 * The window will be allocated in @a pool. 00202 */ 00203 svn_error_t *svn_txdelta_next_window (svn_txdelta_window_t **window, 00204 svn_txdelta_stream_t *stream, 00205 apr_pool_t *pool); 00206 00207 00208 /** Return the @a md5 digest for the complete fulltext deltified by 00209 * @a stream, or @c NULL if @a stream has not yet returned its final 00210 * @c NULL window. The digest is allocated in the same memory as @a 00211 * STREAM. 00212 */ 00213 const unsigned char *svn_txdelta_md5_digest (svn_txdelta_stream_t *stream); 00214 00215 /** Set @a *stream to a pointer to a delta stream that will turn the byte 00216 * string from @a source into the byte stream from @a target. 00217 * 00218 * @a source and @a target are both readable generic streams. When we call 00219 * @c svn_txdelta_next_window on @a *stream, it will read from @a source and 00220 * @a target to gather as much data as it needs. 00221 * 00222 * Do any necessary allocation in a sub-pool of @a pool. 00223 */ 00224 void svn_txdelta (svn_txdelta_stream_t **stream, 00225 svn_stream_t *source, 00226 svn_stream_t *target, 00227 apr_pool_t *pool); 00228 00229 00230 /** 00231 * @since New in 1.1. 00232 * 00233 * Return a writable stream which, when fed target data, will send 00234 * delta windows to @a handler/@a handler_baton which transform the 00235 * data in @a source to the target data. As usual, the window handler 00236 * will receive a NULL window to signify the end of the window stream. 00237 * The stream handler functions will read data from @a source as 00238 * necessary. 00239 */ 00240 svn_stream_t *svn_txdelta_target_push (svn_txdelta_window_handler_t handler, 00241 void *handler_baton, 00242 svn_stream_t *source, 00243 apr_pool_t *pool); 00244 00245 00246 /** Send the contents of @a string to window-handler @a handler/@a baton. 00247 * This is effectively a 'copy' operation, resulting in delta windows that 00248 * make the target equivalent to the value of @a string. 00249 * 00250 * All temporary allocation is performed in @a pool. 00251 */ 00252 svn_error_t *svn_txdelta_send_string (const svn_string_t *string, 00253 svn_txdelta_window_handler_t handler, 00254 void *handler_baton, 00255 apr_pool_t *pool); 00256 00257 /** Send the contents of @a stream to window-handler @a handler/@a baton. 00258 * This is effectively a 'copy' operation, resulting in delta windows that 00259 * make the target equivalent to the stream. 00260 * 00261 * If @a digest is non-null, populate it with the md5 checksum for the 00262 * fulltext that was deltified (@a digest must be at least 00263 * @c APR_MD5_DIGESTSIZE bytes long). 00264 * 00265 * All temporary allocation is performed in @a pool. 00266 */ 00267 svn_error_t *svn_txdelta_send_stream (svn_stream_t *stream, 00268 svn_txdelta_window_handler_t handler, 00269 void *handler_baton, 00270 unsigned char *digest, 00271 apr_pool_t *pool); 00272 00273 /** Send the contents of @a txstream to window-handler @a handler/@a baton. 00274 * Windows will be extracted from the stream and delivered to the handler. 00275 * 00276 * All temporary allocation is performed in @a pool. 00277 */ 00278 svn_error_t *svn_txdelta_send_txstream (svn_txdelta_stream_t *txstream, 00279 svn_txdelta_window_handler_t handler, 00280 void *handler_baton, 00281 apr_pool_t *pool); 00282 00283 00284 /** Prepare to apply a text delta. @a source is a readable generic stream 00285 * yielding the source data, @a target is a writable generic stream to 00286 * write target data to, and allocation takes place in a sub-pool of 00287 * @a pool. On return, @a *handler is set to a window handler function and 00288 * @a *handler_baton is set to the value to pass as the @a baton argument to 00289 * @a *handler. 00290 * 00291 * If @a result_digest is non-null, it points to APR_MD5_DIGESTSIZE bytes 00292 * of storage, and the final call to @a handler populates it with the 00293 * MD5 digest of the resulting fulltext. 00294 * 00295 * If @a error_info is non-null, it is inserted parenthetically into 00296 * the error string for any error returned by svn_txdelta_apply() or 00297 * @a *handler. (It is normally used to provide path information, 00298 * since there's nothing else in the delta application's context to 00299 * supply a path for error messages.) 00300 * 00301 * Note: To avoid lifetime issues, @a error_info is copied into 00302 * @a pool or a subpool thereof. 00303 */ 00304 void svn_txdelta_apply (svn_stream_t *source, 00305 svn_stream_t *target, 00306 unsigned char *result_digest, 00307 const char *error_info, 00308 apr_pool_t *pool, 00309 svn_txdelta_window_handler_t *handler, 00310 void **handler_baton); 00311 00312 00313 00314 /*** Producing and consuming svndiff-format text deltas. ***/ 00315 00316 /** Prepare to produce an svndiff-format diff from text delta windows. 00317 * @a output is a writable generic stream to write the svndiff data to. 00318 * Allocation takes place in a sub-pool of @a pool. On return, @a *handler 00319 * is set to a window handler function and @a *handler_baton is set to 00320 * the value to pass as the @a baton argument to @a *handler. 00321 */ 00322 void svn_txdelta_to_svndiff (svn_stream_t *output, 00323 apr_pool_t *pool, 00324 svn_txdelta_window_handler_t *handler, 00325 void **handler_baton); 00326 00327 /** Return a writable generic stream which will parse svndiff-format 00328 * data into a text delta, invoking @a handler with @a handler_baton 00329 * whenever a new window is ready. If @a error_on_early_close is @c 00330 * TRUE, attempting to close this stream before it has handled the entire 00331 * svndiff data set will result in @c SVN_ERR_SVNDIFF_UNEXPECTED_END, 00332 * else this error condition will be ignored. 00333 */ 00334 svn_stream_t *svn_txdelta_parse_svndiff (svn_txdelta_window_handler_t handler, 00335 void *handler_baton, 00336 svn_boolean_t error_on_early_close, 00337 apr_pool_t *pool); 00338 00339 /** 00340 * @since New in 1.1. 00341 * 00342 * Read and parse one delta window in svndiff format from the 00343 * readable stream @a stream and place it in @a *window, allocating 00344 * the result in @a pool. The caller must take responsibility for 00345 * stripping off the four-byte 'SVN@<ver@>' header at the beginning of 00346 * the svndiff document before reading the first window, and must 00347 * provide the version number (the value of the fourth byte) to each 00348 * invocation of this routine with the @a svndiff_version argument. */ 00349 svn_error_t *svn_txdelta_read_svndiff_window (svn_txdelta_window_t **window, 00350 svn_stream_t *stream, 00351 int svndiff_version, 00352 apr_pool_t *pool); 00353 00354 /** 00355 * @since New in 1.1. 00356 * 00357 * Skip one delta window in svndiff format in the file @a file. and 00358 * place it in @a *window, allocating the result in @a pool. The 00359 * caller must take responsibility for stripping off the four-byte 00360 * 'SVN@<ver@>' header at the beginning of the svndiff document before 00361 * reading or skipping the first window, and must provide the version 00362 * number (the value of the fourth byte) to each invocation of this 00363 * routine with the @a svndiff_version argument. */ 00364 svn_error_t *svn_txdelta_skip_svndiff_window (apr_file_t *file, 00365 int svndiff_version, 00366 apr_pool_t *pool); 00367 00368 /** @} */ 00369 00370 00371 /** Traversing tree deltas. 00372 * 00373 * In Subversion, we've got various producers and consumers of tree 00374 * deltas. 00375 * 00376 * In processing a `commit' command: 00377 * - The client examines its working copy data, and produces a tree 00378 * delta describing the changes to be committed. 00379 * - The client networking library consumes that delta, and sends them 00380 * across the wire as an equivalent series of WebDAV requests. 00381 * - The Apache WebDAV module receives those requests and produces a 00382 * tree delta --- hopefully equivalent to the one the client 00383 * produced above. 00384 * - The Subversion server module consumes that delta and commits an 00385 * appropriate transaction to the filesystem. 00386 * 00387 * In processing an `update' command, the process is reversed: 00388 * - The Subversion server module talks to the filesystem and produces 00389 * a tree delta describing the changes necessary to bring the 00390 * client's working copy up to date. 00391 * - The Apache WebDAV module consumes this delta, and assembles a 00392 * WebDAV reply representing the appropriate changes. 00393 * - The client networking library receives that WebDAV reply, and 00394 * produces a tree delta --- hopefully equivalent to the one the 00395 * Subversion server produced above. 00396 * - The working copy library consumes that delta, and makes the 00397 * appropriate changes to the working copy. 00398 * 00399 * The simplest approach would be to represent tree deltas using the 00400 * obvious data structure. To do an update, the server would 00401 * construct a delta structure, and the working copy library would 00402 * apply that structure to the working copy; WebDAV's job would simply 00403 * be to get the structure across the net intact. 00404 * 00405 * However, we expect that these deltas will occasionally be too large 00406 * to fit in a typical workstation's swap area. For example, in 00407 * checking out a 200Mb source tree, the entire source tree is 00408 * represented by a single tree delta. So it's important to handle 00409 * deltas that are too large to fit in swap all at once. 00410 * 00411 * So instead of representing the tree delta explicitly, we define a 00412 * standard way for a consumer to process each piece of a tree delta 00413 * as soon as the producer creates it. The @c svn_delta_editor_t 00414 * structure is a set of callback functions to be defined by a delta 00415 * consumer, and invoked by a delta producer. Each invocation of a 00416 * callback function describes a piece of the delta --- a file's 00417 * contents changing, something being renamed, etc. 00418 * 00419 * @defgroup svn_delta_tree_deltas tree deltas 00420 * @{ 00421 */ 00422 00423 /** A structure full of callback functions the delta source will invoke 00424 * as it produces the delta. 00425 * 00426 * <h3>Function Usage</h3> 00427 * 00428 * Here's how to use these functions to express a tree delta. 00429 * 00430 * The delta consumer implements the callback functions described in 00431 * this structure, and the delta producer invokes them. So the 00432 * caller (producer) is pushing tree delta data at the callee 00433 * (consumer). 00434 * 00435 * At the start of traversal, the consumer provides @a edit_baton, a 00436 * baton global to the entire delta edit. If there is a target 00437 * revision that needs to be set for this operation, the producer 00438 * should called the @c set_target_revision function at this point. 00439 * 00440 * Next, if there are any tree deltas to express, the producer should 00441 * pass the @a edit_baton to the @c open_root function, to get a baton 00442 * representing root of the tree being edited. 00443 * 00444 * Most of the callbacks work in the obvious way: 00445 * 00446 * @c delete_entry 00447 * @c add_file 00448 * @c add_directory 00449 * @c open_file 00450 * @c open_directory 00451 * 00452 * Each of these takes a directory baton, indicating the directory 00453 * in which the change takes place, and a @a path argument, giving the 00454 * path (relative to the root of the edit) of the file, 00455 * subdirectory, or directory entry to change. Editors will usually 00456 * want to join this relative path with some base stored in the edit 00457 * baton (e.g. a URL, a location in the OS filesystem). 00458 * 00459 * Since every call requires a parent directory baton, including 00460 * add_directory and open_directory, where do we ever get our 00461 * initial directory baton, to get things started? The @c open_root 00462 * function returns a baton for the top directory of the change. In 00463 * general, the producer needs to invoke the editor's @c open_root 00464 * function before it can get anything of interest done. 00465 * 00466 * While @c open_root provides a directory baton for the root of 00467 * the tree being changed, the @c add_directory and @c open_directory 00468 * callbacks provide batons for other directories. Like the 00469 * callbacks above, they take a @a parent_baton and a relative path 00470 * @a path, and then return a new baton for the subdirectory being 00471 * created / modified --- @a child_baton. The producer can then use 00472 * @a child_baton to make further changes in that subdirectory. 00473 * 00474 * So, if we already have subdirectories named `foo' and `foo/bar', 00475 * then the producer can create a new file named `foo/bar/baz.c' by 00476 * calling: 00477 * 00478 * - @c open_root () --- yielding a baton @a root for the top directory 00479 * 00480 * - @c open_directory (@a root, "foo") --- yielding a baton @a f for `foo' 00481 * 00482 * - @c open_directory (@a f, "foo/bar") --- yielding a baton @a b for 00483 * `foo/bar' 00484 * 00485 * - @c add_file (@a b, "foo/bar/baz.c") 00486 * 00487 * When the producer is finished making changes to a directory, it 00488 * should call @c close_directory. This lets the consumer do any 00489 * necessary cleanup, and free the baton's storage. 00490 * 00491 * The @c add_file and @c open_file callbacks each return a baton 00492 * for the file being created or changed. This baton can then be 00493 * passed to @c apply_textdelta to change the file's contents, or 00494 * @c change_file_prop to change the file's properties. When the 00495 * producer is finished making changes to a file, it should call 00496 * @c close_file, to let the consumer clean up and free the baton. 00497 * 00498 * The @c add_file and @c add_directory functions each take arguments 00499 * @a copyfrom_path and @a copyfrom_revision. If @a copyfrom_path is 00500 * non-@c NULL, then @a copyfrom_path and @a copyfrom_revision indicate where 00501 * the file or directory should be copied from (to create the file 00502 * or directory being added). If @a copyfrom_path is @c NULL, then 00503 * @a copyfrom_revision must be @c SVN_INVALID_REVNUM; it is invalid to 00504 * pass a mix of valid and invalid copyfrom arguments. 00505 * 00506 * 00507 * <h3>Function Call Ordering</h3> 00508 * 00509 * There are six restrictions on the order in which the producer 00510 * may use the batons: 00511 * 00512 * 1. The producer may call @c open_directory, @c add_directory, 00513 * @c open_file, @c add_file at most once on any given directory 00514 * entry. @c delete_entry may be called at most once on any given 00515 * directory entry and may later be followed by @c add_directory or 00516 * @c add_file on the same directory entry. @c delete_entry may 00517 * not be called on any directory entry after @c open_directory, 00518 * @c add_directory, @c open_file or @c add_file has been called on 00519 * that directory entry. 00520 * 00521 * 2. The producer may not close a directory baton until it has 00522 * closed all batons for its subdirectories. 00523 * 00524 * 3. When a producer calls @c open_directory or @c add_directory, 00525 * it must specify the most recently opened of the currently open 00526 * directory batons. Put another way, the producer cannot have 00527 * two sibling directory batons open at the same time. 00528 * 00529 * 4. A producer must call @c change_dir_prop on a directory either 00530 * before opening any of the directory's subdirs or after closing 00531 * them, but not in the middle. 00532 * 00533 * 5. When the producer calls @c open_file or @c add_file, either: 00534 * 00535 * (a) The producer must follow with the changes to the file 00536 * (@c change_file_prop and/or @c apply_textdelta, as applicable) 00537 * followed by a @c close_file call, before issuing any other file 00538 * or directory calls, or 00539 * 00540 * (b) The producer must follow with a @c change_file_prop call if 00541 * it is applicable, before issuing any other file or directory 00542 * calls; later, after all directory batons including the root 00543 * have been closed, the producer must issue @c apply_textdelta 00544 * and @c close_file calls. 00545 * 00546 * 6. When the producer calls @c apply_textdelta, it must make all of 00547 * the window handler calls (including the @c NULL window at the 00548 * end) before issuing any other @c svn_delta_editor_t calls. 00549 * 00550 * So, the producer needs to use directory and file batons as if it 00551 * is doing a single depth-first traversal of the tree, with the 00552 * exception that the producer may keep file batons open in order to 00553 * make apply_textdelta calls at the end. 00554 * 00555 * 00556 * <h3>Pool Usage</h3> 00557 * 00558 * Many editor functions are invoked multiple times, in a sequence 00559 * determined by the editor "driver". The driver is responsible for 00560 * creating a pool for use on each iteration of the editor function, 00561 * and clearing that pool between each iteration. The driver passes 00562 * the appropriate pool on each function invocation. 00563 * 00564 * Based on the requirement of calling the editor functions in a 00565 * depth-first style, it is usually customary for the driver to similar 00566 * nest the pools. However, this is only a safety feature to ensure 00567 * that pools associated with deeper items are always cleared when the 00568 * top-level items are also cleared. The interface does not assume, nor 00569 * require, any particular organization of the pools passed to these 00570 * functions. In fact, if "postfix deltas" are used for files, the file 00571 * pools definitely need to live outside the scope of their parent 00572 * directories' pools. 00573 * 00574 * Note that close_directory can be called *before* a file in that 00575 * directory has been closed. That is, the directory's baton is 00576 * closed before the file's baton. The implication is that 00577 * @c apply_textdelta and @c close_file should not refer to a parent 00578 * directory baton UNLESS the editor has taken precautions to 00579 * allocate it in a pool of the appropriate lifetime (the @a dir_pool 00580 * passed to @c open_directory and @c add_directory definitely does not 00581 * have the proper lifetime). In general, it is recommended to simply 00582 * avoid keeping a parent directory baton in a file baton. 00583 * 00584 * 00585 * <h3>Errors</h3> 00586 * 00587 * At least one implementation of the editor interface is 00588 * asynchronous; an error from one operation may be detected some 00589 * number of operations later. As a result, an editor driver must not 00590 * assume that an error from an editing function resulted from the 00591 * particular operation being detected. Moreover, once an editing 00592 * function returns an error, the edit is dead; the only further 00593 * operation which may be called on the editor is abort_edit. 00594 */ 00595 typedef struct svn_delta_editor_t 00596 { 00597 /** Set the target revision for this edit to @a target_revision. This 00598 * call, if used, should precede all other editor calls. 00599 */ 00600 svn_error_t *(*set_target_revision) (void *edit_baton, 00601 svn_revnum_t target_revision, 00602 apr_pool_t *pool); 00603 00604 /** Set @a *root_baton to a baton for the top directory of the change. 00605 * (This is the top of the subtree being changed, not necessarily 00606 * the root of the filesystem.) Like any other directory baton, the 00607 * producer should call @c close_directory on @a root_baton when they're 00608 * done. And like other @c open_* calls, the @a base_revision here is 00609 * the current revision of the directory (before getting bumped up 00610 * to the new target revision set with @c set_target_revision). 00611 * 00612 * Allocations for the returned @a root_baton should be performed in 00613 * @a dir_pool. It is also typical to (possibly) save this pool for later 00614 * usage by @c close_directory. 00615 */ 00616 svn_error_t *(*open_root) (void *edit_baton, 00617 svn_revnum_t base_revision, 00618 apr_pool_t *dir_pool, 00619 void **root_baton); 00620 00621 00622 /** Remove the directory entry named @a path, a child of the directory 00623 * represented by @a parent_baton. If @a revision is set, it is used as a 00624 * sanity check to ensure that you are removing the revision of @a path 00625 * that you really think you are. 00626 * 00627 * All allocations should be performed in @a pool. 00628 */ 00629 svn_error_t *(*delete_entry) (const char *path, 00630 svn_revnum_t revision, 00631 void *parent_baton, 00632 apr_pool_t *pool); 00633 00634 00635 /** We are going to add a new subdirectory named @a path. We will use 00636 * the value this callback stores in @a *child_baton as the 00637 * @a parent_baton for further changes in the new subdirectory. 00638 * 00639 * If @a copyfrom_path is non-@c NULL, this add has history (i.e., is a 00640 * copy), and the origin of the copy may be recorded as 00641 * @a copyfrom_path under @a copyfrom_revision. 00642 * 00643 * Allocations for the returned @a child_baton should be performed in 00644 * @a dir_pool. It is also typical to (possibly) save this pool for later 00645 * usage by @c close_directory. 00646 */ 00647 svn_error_t *(*add_directory) (const char *path, 00648 void *parent_baton, 00649 const char *copyfrom_path, 00650 svn_revnum_t copyfrom_revision, 00651 apr_pool_t *dir_pool, 00652 void **child_baton); 00653 00654 /** We are going to make changes in a subdirectory (of the directory 00655 * identified by @a parent_baton). The subdirectory is specified by 00656 * @a path. The callback must store a value in @a *child_baton that 00657 * should be used as the @a parent_baton for subsequent changes in this 00658 * subdirectory. If a valid revnum, @a base_revision is the current 00659 * revision of the subdirectory. 00660 * 00661 * Allocations for the returned @a child_baton should be performed in 00662 * @a dir_pool. It is also typical to (possibly) save this pool for later 00663 * usage by @c close_directory. 00664 */ 00665 svn_error_t *(*open_directory) (const char *path, 00666 void *parent_baton, 00667 svn_revnum_t base_revision, 00668 apr_pool_t *dir_pool, 00669 void **child_baton); 00670 00671 /** Change the value of a directory's property. 00672 * - @a dir_baton specifies the directory whose property should change. 00673 * - @a name is the name of the property to change. 00674 * - @a value is the new value of the property, or @c NULL if the property 00675 * should be removed altogether. 00676 * 00677 * All allocations should be performed in @a pool. 00678 */ 00679 svn_error_t *(*change_dir_prop) (void *dir_baton, 00680 const char *name, 00681 const svn_string_t *value, 00682 apr_pool_t *pool); 00683 00684 /** We are done processing a subdirectory, whose baton is @a dir_baton 00685 * (set by @c add_directory or @c open_directory). We won't be using 00686 * the baton any more, so whatever resources it refers to may now be 00687 * freed. 00688 */ 00689 svn_error_t *(*close_directory) (void *dir_baton, 00690 apr_pool_t *pool); 00691 00692 00693 /** In the directory represented by @a parent_baton, indicate that 00694 * @a path is present as a subdirectory in the edit source, but 00695 * cannot be conveyed to the edit consumer (perhaps because of 00696 * authorization restrictions). 00697 */ 00698 svn_error_t *(*absent_directory) (const char *path, 00699 void *parent_baton, 00700 apr_pool_t *pool); 00701 00702 /** We are going to add a new file named @a path. The callback can 00703 * store a baton for this new file in @a **file_baton; whatever value 00704 * it stores there should be passed through to @c apply_textdelta. 00705 * 00706 * If @a copyfrom_path is non-@c NULL, this add has history (i.e., is a 00707 * copy), and the origin of the copy may be recorded as 00708 * @a copyfrom_path under @a copyfrom_revision. 00709 * 00710 * Allocations for the returned @a file_baton should be performed in 00711 * @a file_pool. It is also typical to save this pool for later usage 00712 * by @c apply_textdelta and possibly @c close_file. 00713 */ 00714 svn_error_t *(*add_file) (const char *path, 00715 void *parent_baton, 00716 const char *copy_path, 00717 svn_revnum_t copy_revision, 00718 apr_pool_t *file_pool, 00719 void **file_baton); 00720 00721 /** We are going to make change to a file named @a path, which resides 00722 * in the directory identified by @a parent_baton. 00723 * 00724 * The callback can store a baton for this new file in @a **file_baton; 00725 * whatever value it stores there should be passed through to 00726 * apply_textdelta. If a valid revnum, @a base_revision is the 00727 * current revision of the file. 00728 * 00729 * Allocations for the returned @a file_baton should be performed in 00730 * @a file_pool. It is also typical to save this pool for later usage 00731 * by @c apply_textdelta and possibly @c close_file. 00732 */ 00733 svn_error_t *(*open_file) (const char *path, 00734 void *parent_baton, 00735 svn_revnum_t base_revision, 00736 apr_pool_t *file_pool, 00737 void **file_baton); 00738 00739 /** Apply a text delta, yielding the new revision of a file. 00740 * 00741 * @a file_baton indicates the file we're creating or updating, and the 00742 * ancestor file on which it is based; it is the baton set by some 00743 * prior @c add_file or @c open_file callback. 00744 * 00745 * The callback should set @a *handler to a text delta window 00746 * handler; we will then call @a *handler on successive text 00747 * delta windows as we receive them. The callback should set 00748 * @a *handler_baton to the value we should pass as the @a baton 00749 * argument to @a *handler. 00750 * 00751 * @a base_checksum is the hex MD5 digest for the base text against 00752 * which the delta is being applied; it is ignored if null, and may 00753 * be ignored even if not null. If it is not ignored, it must match 00754 * the checksum of the base text against which svndiff data is being 00755 * applied; if it does not, apply_textdelta or the @a *handler call 00756 * which detects the mismatch will return the error 00757 * SVN_ERR_CHECKSUM_MISMATCH (if there is no base text, there may 00758 * still be an error if @a base_checksum is neither null nor the hex 00759 * MD5 checksum of the empty string). 00760 */ 00761 svn_error_t *(*apply_textdelta) (void *file_baton, 00762 const char *base_checksum, 00763 apr_pool_t *pool, 00764 svn_txdelta_window_handler_t *handler, 00765 void **handler_baton); 00766 00767 /** Change the value of a file's property. 00768 * - @a file_baton specifies the file whose property should change. 00769 * - @a name is the name of the property to change. 00770 * - @a value is the new value of the property, or @c NULL if the property 00771 * should be removed altogether. 00772 * 00773 * All allocations should be performed in @a pool. 00774 */ 00775 svn_error_t *(*change_file_prop) (void *file_baton, 00776 const char *name, 00777 const svn_string_t *value, 00778 apr_pool_t *pool); 00779 00780 /** We are done processing a file, whose baton is @a file_baton (set by 00781 * @c add_file or @c open_file). We won't be using the baton any 00782 * more, so whatever resources it refers to may now be freed. 00783 * 00784 * @a text_checksum is the hex MD5 digest for the fulltext that 00785 * resulted from a delta application, see @c apply_textdelta. The 00786 * checksum is ignored if null. If not null, it is compared to the 00787 * checksum of the new fulltext, and the error 00788 * SVN_ERR_CHECKSUM_MISMATCH is returned if they do not match. If 00789 * there is no new fulltext, @a text_checksum is ignored. 00790 */ 00791 svn_error_t *(*close_file) (void *file_baton, 00792 const char *text_checksum, 00793 apr_pool_t *pool); 00794 00795 /** In the directory represented by @a parent_baton, indicate that 00796 * @a path is present as a file in the edit source, but cannot be 00797 * conveyed to the edit consumer (perhaps because of authorization 00798 * restrictions). 00799 */ 00800 svn_error_t *(*absent_file) (const char *path, 00801 void *parent_baton, 00802 apr_pool_t *pool); 00803 00804 /** All delta processing is done. Call this, with the @a edit_baton for 00805 * the entire edit. 00806 */ 00807 svn_error_t *(*close_edit) (void *edit_baton, 00808 apr_pool_t *pool); 00809 00810 /** The editor-driver has decided to bail out. Allow the editor to 00811 * gracefully clean up things if it needs to. 00812 */ 00813 svn_error_t *(*abort_edit) (void *edit_baton, 00814 apr_pool_t *pool); 00815 00816 } svn_delta_editor_t; 00817 00818 00819 /** Return a default delta editor template, allocated in @a pool. 00820 * 00821 * The editor functions in the template do only the most basic 00822 * baton-swapping: each editor function that produces a baton does so 00823 * by copying its incoming baton into the outgoing baton reference. 00824 * 00825 * This editor is not intended to be useful by itself, but is meant to 00826 * be the basis for a useful editor. After getting a default editor, 00827 * you substitute in your own implementations for the editor functions 00828 * you care about. The ones you don't care about, you don't have to 00829 * implement -- you can rely on the template's implementation to 00830 * safely do nothing of consequence. 00831 */ 00832 svn_delta_editor_t *svn_delta_default_editor (apr_pool_t *pool); 00833 00834 /** A text-delta window handler which does nothing. 00835 * 00836 * Editors can return this handler from apply_textdelta if they don't 00837 * care about text delta windows. 00838 */ 00839 svn_error_t *svn_delta_noop_window_handler (svn_txdelta_window_t *window, 00840 void *baton); 00841 00842 /** Return a cancellation editor that wraps @a wrapped_editor. 00843 * 00844 * The @a editor will call @a cancel_func with @a cancel_baton when each of 00845 * its functions is called, continuing on to call the corresponding wrapped 00846 * function if it returns @c SVN_NO_ERROR. 00847 * 00848 * If @a cancel_func is @c NULL, @a *editor is set to @a wrapped_editor and 00849 * @a *edit_baton is set to @a wrapped_baton. 00850 */ 00851 svn_error_t * 00852 svn_delta_get_cancellation_editor (svn_cancel_func_t cancel_func, 00853 void *cancel_baton, 00854 const svn_delta_editor_t *wrapped_editor, 00855 void *wrapped_baton, 00856 const svn_delta_editor_t **editor, 00857 void **edit_baton, 00858 apr_pool_t *pool); 00859 00860 /** @} */ 00861 00862 00863 /** Path-based editor drives. 00864 * 00865 * @defgroup svn_delta_path_delta_drivers path-based delta drivers 00866 * @{ 00867 */ 00868 00869 /** Callback function type for svn_delta_path_driver(). 00870 * 00871 * The handler of this callback is given the callback baton @a 00872 * callback_baton, @a path, and the @a parent_baton which represents 00873 * path's parent directory as created by the editor passed to 00874 * svn_delta_path_driver(). 00875 * 00876 * If @a path represents a directory, the handler must return a @a 00877 * *dir_baton for @a path, generated from the same editor (so that the 00878 * driver can later close that directory). 00879 * 00880 * If, however, @a path represents a file, the handler should NOT 00881 * return any file batons. It can close any opened or added files 00882 * immediately, or delay that close until the end of the edit when 00883 * svn_delta_path_driver() returns. 00884 * 00885 * Finally, if @a parent_baton is @c NULL, then the root of the edit 00886 * is also one of the paths passed to svn_delta_path_driver(). The 00887 * handler of this callback must call the editor's open_root() 00888 * function and return the top-level root dir baton in @a *dir_baton. 00889 */ 00890 typedef svn_error_t * 00891 (*svn_delta_path_driver_cb_func_t) (void **dir_baton, 00892 void *parent_baton, 00893 void *callback_baton, 00894 const char *path, 00895 apr_pool_t *pool); 00896 00897 00898 /** Drive @a editor (with its @a edit_baton) in such a way that 00899 * each path in @a paths is traversed in a depth-first fashion. As 00900 * each path is hit as part of the editor drive, use @a 00901 * callback_func and @a callback_baton to allow the caller to handle 00902 * the portion of the editor drive related to that path. 00903 * 00904 * Use @a revision as the revision number passed to intermediate 00905 * directory openings. 00906 * 00907 * Use @a pool for all necessary allocations. 00908 */ 00909 svn_error_t * 00910 svn_delta_path_driver (const svn_delta_editor_t *editor, 00911 void *edit_baton, 00912 svn_revnum_t revision, 00913 apr_array_header_t *paths, 00914 svn_delta_path_driver_cb_func_t callback_func, 00915 void *callback_baton, 00916 apr_pool_t *pool); 00917 00918 /** @} */ 00919 00920 00921 #ifdef __cplusplus 00922 } 00923 #endif /* __cplusplus */ 00924 00925 #endif /* SVN_DELTA_H */