/** * @copyright * ==================================================================== * Copyright (c) 2000-2008 CollabNet. All rights reserved. * * This software is licensed as described in the file COPYING, which * you should have received as part of this distribution. The terms * are also available at http://subversion.tigris.org/license-1.html. * If newer versions of this license are posted there, you may use a * newer version instead, at your option. * * This software consists of voluntary contributions made by many * individuals. For exact contribution history, see the revision * history and logs, available at http://subversion.tigris.org/. * ==================================================================== * @endcopyright * * @file svn_delta.h * @brief Delta-parsing */ /* ==================================================================== */ #ifndef SVN_DELTA_H #define SVN_DELTA_H #include #include #include #include #include /* for apr_file_t */ #include "svn_types.h" #include "svn_string.h" #include "svn_io.h" #include "svn_version.h" #include "svn_checksum.h" #ifdef __cplusplus extern "C" { #endif /* __cplusplus */ /** * Get libsvn_delta version information. * * @since New in 1.1. */ const svn_version_t * svn_delta_version(void); /** * @defgroup delta_support Delta generation and handling * * @{ */ /** Text deltas. * * A text delta represents the difference between two strings of * bytes, the `source' string and the `target' string. Given a source * string and a target string, we can compute a text delta; given a * source string and a delta, we can reconstruct the target string. * However, note that deltas are not reversible: you cannot always * reconstruct the source string given the target string and delta. * * Since text deltas can be very large, the interface here allows us * to produce and consume them in pieces. Each piece, represented by * an @c svn_txdelta_window_t structure, describes how to produce the * next section of the target string. * * To compute a new text delta: * * - We call svn_txdelta() on the streams we want to compare. That * returns us an @c svn_txdelta_stream_t object. * * - We then call svn_txdelta_next_window() on the stream object * repeatedly. Each call returns a new @c svn_txdelta_window_t * object, which describes the next portion of the target string. * When svn_txdelta_next_window() returns zero, we are done building * the target string. * * @defgroup svn_delta_txt_delta Text deltas * @{ */ /** Action codes for text delta instructions. */ enum svn_delta_action { /** Append the @a length bytes at @a offset in the source view to the * target. * * It must be the case that 0 <= @a offset < @a offset + * @a length <= size of source view. */ svn_txdelta_source, /** Append the @a length bytes at @a offset in the target view, to the * target. * * It must be the case that 0 <= @a offset < current position in the * target view. * * However! @a offset + @a length may be *beyond* the end of the existing * target data. "Where the heck does the text come from, then?" * If you start at @a offset, and append @a length bytes one at a time, * it'll work out --- you're adding new bytes to the end at the * same rate you're reading them from the middle. Thus, if your * current target text is "abcdefgh", and you get an @c svn_txdelta_target * instruction whose @a offset is 6 and whose @a length is 7, * the resulting string is "abcdefghghghghg". This trick is actually * useful in encoding long runs of consecutive characters, long runs * of CR/LF pairs, etc. */ svn_txdelta_target, /** Append the @a length bytes at @a offset in the window's @a new string * to the target. * * It must be the case that 0 <= @a offset < @a offset + * @a length <= length of @a new. Windows MUST use new data in ascending * order with no overlap at the moment; svn_txdelta_to_svndiff() * depends on this. */ svn_txdelta_new }; /** A single text delta instruction. */ typedef struct svn_txdelta_op_t { /** Action code of delta instruction */ enum svn_delta_action action_code; /** Offset of delta, see #svn_delta_action for more details. */ apr_size_t offset; /** Number of bytes of delta, see #svn_delta_action for more details. */ apr_size_t length; } svn_txdelta_op_t; /** An @c svn_txdelta_window_t object describes how to reconstruct a * contiguous section of the target string (the "target view") using a * specified contiguous region of the source string (the "source * view"). It contains a series of instructions which assemble the * new target string text by pulling together substrings from: * * - the source view, * * - the previously constructed portion of the target view, * * - a string of new data contained within the window structure * * The source view must always slide forward from one window to the * next; that is, neither the beginning nor the end of the source view * may move to the left as we read from a window stream. This * property allows us to apply deltas to non-seekable source streams * without making a full copy of the source stream. */ typedef struct svn_txdelta_window_t { /** The offset of the source view for this window. */ svn_filesize_t sview_offset; /** The length of the source view for this window. */ apr_size_t sview_len; /** The length of the target view for this window, i.e. the number of * bytes which will be reconstructed by the instruction stream. */ apr_size_t tview_len; /** The number of instructions in this window. */ int num_ops; /** The number of svn_txdelta_source instructions in this window. If * this number is 0, we don't need to read the source in order to * reconstruct the target view. */ int src_ops; /** The instructions for this window. */ const svn_txdelta_op_t *ops; /** New data, for use by any `svn_txdelta_new' instructions. */ const svn_string_t *new_data; } svn_txdelta_window_t; /** * Return a deep copy of @a window, allocated in @a pool. * * @since New in 1.3. */ svn_txdelta_window_t * svn_txdelta_window_dup(const svn_txdelta_window_t *window, apr_pool_t *pool); /** * Compose two delta windows, yielding a third, allocated in @a pool. * * @since New in 1.4 * */ svn_txdelta_window_t * svn_txdelta_compose_windows(const svn_txdelta_window_t *window_A, const svn_txdelta_window_t *window_B, apr_pool_t *pool); /** * Apply the instructions from @a window to a source view @a sbuf to * produce a target view @a tbuf. * * @a sbuf is assumed to have @a window->sview_len bytes of data and * @a tbuf is assumed to have room for @a tlen bytes of output. @a * tlen may be more than @a window->tview_len, so return the actual * number of bytes written. @a sbuf is not touched and may be NULL if * @a window contains no source-copy operations. This is purely a * memory operation; nothing can go wrong as long as we have a valid * window. * * @since New in 1.4 * */ void svn_txdelta_apply_instructions(svn_txdelta_window_t *window, const char *sbuf, char *tbuf, apr_size_t *tlen); /** A typedef for functions that consume a series of delta windows, for * use in caller-pushes interfaces. Such functions will typically * apply the delta windows to produce some file, or save the windows * somewhere. At the end of the delta window stream, you must call * this function passing zero for the @a window argument. */ typedef svn_error_t *(*svn_txdelta_window_handler_t) (svn_txdelta_window_t *window, void *baton); /** This function will generate delta windows that turn @a source into * @a target, and pushing these windows into the @a handler window handler * callback (passing @a handler_baton to each invocation). * * If @a checksum is not NULL, then a checksum (of kind @a checksum_kind) * will be computed for the target stream, and placed into *checksum. * * If @a cancel_func is not NULL, then it should refer to a cancellation * function (along with @a cancel_baton). * * Results (the checksum) will be allocated from @a result_pool, and all * temporary allocations will be performed in @a scratch_pool. * * Note: this function replaces the combination of svn_txdelta() and * svn_txdelta_send_txstream(). * * @since New in 1.6. */ svn_error_t * svn_txdelta_run(svn_stream_t *source, svn_stream_t *target, svn_txdelta_window_handler_t handler, void *handler_baton, svn_checksum_kind_t checksum_kind, svn_checksum_t **checksum, svn_cancel_func_t cancel_func, void *cancel_baton, apr_pool_t *result_pool, apr_pool_t *scratch_pool); /** A delta stream --- this is the hat from which we pull a series of * svn_txdelta_window_t objects, which, taken in order, describe the * entire target string. This type is defined within libsvn_delta, and * opaque outside that library. */ typedef struct svn_txdelta_stream_t svn_txdelta_stream_t; /** A typedef for a function that will set @a *window to the next * window from a @c svn_txdelta_stream_t object. If there are no more * delta windows, NULL will be used. The returned window, if any, * will be allocated in @a pool. @a baton is the baton specified * when the stream was created. * * @since New in 1.4. */ typedef svn_error_t * (*svn_txdelta_next_window_fn_t)(svn_txdelta_window_t **window, void *baton, apr_pool_t *pool); /** A typedef for a function that will return the md5 checksum of the * fulltext deltified by a @c svn_txdelta_stream_t object. Will * return NULL if the final null window hasn't yet been returned by * the stream. The returned value will be allocated in the same pool * as the stream. @a baton is the baton specified when the stream was * created. * * @since New in 1.4. */ typedef const unsigned char * (*svn_txdelta_md5_digest_fn_t)(void *baton); /** Create and return a generic text delta stream with @a baton, @a * next_window and @a md5_digest. Allocate the new stream in @a * pool. * * @since New in 1.4. */ svn_txdelta_stream_t * svn_txdelta_stream_create(void *baton, svn_txdelta_next_window_fn_t next_window, svn_txdelta_md5_digest_fn_t md5_digest, apr_pool_t *pool); /** Set @a *window to a pointer to the next window from the delta stream * @a stream. When we have completely reconstructed the target string, * set @a *window to zero. * * The window will be allocated in @a pool. */ svn_error_t * svn_txdelta_next_window(svn_txdelta_window_t **window, svn_txdelta_stream_t *stream, apr_pool_t *pool); /** Return the md5 digest for the complete fulltext deltified by * @a stream, or @c NULL if @a stream has not yet returned its final * @c NULL window. The digest is allocated in the same memory as @a * STREAM. */ const unsigned char * svn_txdelta_md5_digest(svn_txdelta_stream_t *stream); /** Set @a *stream to a pointer to a delta stream that will turn the byte * string from @a source into the byte stream from @a target. * * @a source and @a target are both readable generic streams. When we call * svn_txdelta_next_window() on @a *stream, it will read from @a source and * @a target to gather as much data as it needs. * * Do any necessary allocation in a sub-pool of @a pool. */ void svn_txdelta(svn_txdelta_stream_t **stream, svn_stream_t *source, svn_stream_t *target, apr_pool_t *pool); /** * Return a writable stream which, when fed target data, will send * delta windows to @a handler/@a handler_baton which transform the * data in @a source to the target data. As usual, the window handler * will receive a NULL window to signify the end of the window stream. * The stream handler functions will read data from @a source as * necessary. * * @since New in 1.1. */ svn_stream_t * svn_txdelta_target_push(svn_txdelta_window_handler_t handler, void *handler_baton, svn_stream_t *source, apr_pool_t *pool); /** Send the contents of @a string to window-handler @a handler/@a baton. * This is effectively a 'copy' operation, resulting in delta windows that * make the target equivalent to the value of @a string. * * All temporary allocation is performed in @a pool. */ svn_error_t * svn_txdelta_send_string(const svn_string_t *string, svn_txdelta_window_handler_t handler, void *handler_baton, apr_pool_t *pool); /** Send the contents of @a stream to window-handler @a handler/@a baton. * This is effectively a 'copy' operation, resulting in delta windows that * make the target equivalent to the stream. * * If @a digest is non-NULL, populate it with the md5 checksum for the * fulltext that was deltified (@a digest must be at least * @c APR_MD5_DIGESTSIZE bytes long). * * All temporary allocation is performed in @a pool. */ svn_error_t * svn_txdelta_send_stream(svn_stream_t *stream, svn_txdelta_window_handler_t handler, void *handler_baton, unsigned char *digest, apr_pool_t *pool); /** Send the contents of @a txstream to window-handler @a handler/@a baton. * Windows will be extracted from the stream and delivered to the handler. * * All temporary allocation is performed in @a pool. */ svn_error_t * svn_txdelta_send_txstream(svn_txdelta_stream_t *txstream, svn_txdelta_window_handler_t handler, void *handler_baton, apr_pool_t *pool); /** Prepare to apply a text delta. @a source is a readable generic stream * yielding the source data, @a target is a writable generic stream to * write target data to, and allocation takes place in a sub-pool of * @a pool. On return, @a *handler is set to a window handler function and * @a *handler_baton is set to the value to pass as the @a baton argument to * @a *handler. * * If @a result_digest is non-NULL, it points to APR_MD5_DIGESTSIZE bytes * of storage, and the final call to @a handler populates it with the * MD5 digest of the resulting fulltext. * * If @a error_info is non-NULL, it is inserted parenthetically into * the error string for any error returned by svn_txdelta_apply() or * @a *handler. (It is normally used to provide path information, * since there's nothing else in the delta application's context to * supply a path for error messages.) * * @note To avoid lifetime issues, @a error_info is copied into * @a pool or a subpool thereof. */ void svn_txdelta_apply(svn_stream_t *source, svn_stream_t *target, unsigned char *result_digest, const char *error_info, apr_pool_t *pool, svn_txdelta_window_handler_t *handler, void **handler_baton); /*** Producing and consuming svndiff-format text deltas. ***/ /** Prepare to produce an svndiff-format diff from text delta windows. * @a output is a writable generic stream to write the svndiff data to. * Allocation takes place in a sub-pool of @a pool. On return, @a *handler * is set to a window handler function and @a *handler_baton is set to * the value to pass as the @a baton argument to @a *handler. The svndiff * version is @a svndiff_version. * * @since New in 1.4. */ void svn_txdelta_to_svndiff2(svn_txdelta_window_handler_t *handler, void **handler_baton, svn_stream_t *output, int svndiff_version, apr_pool_t *pool); /** Similar to svn_txdelta_to_svndiff2, but always using svndiff * version 0. * * @deprecated Provided for backward compatibility with the 1.3 API. */ SVN_DEPRECATED void svn_txdelta_to_svndiff(svn_stream_t *output, apr_pool_t *pool, svn_txdelta_window_handler_t *handler, void **handler_baton); /** Return a writable generic stream which will parse svndiff-format * data into a text delta, invoking @a handler with @a handler_baton * whenever a new window is ready. If @a error_on_early_close is @c * TRUE, attempting to close this stream before it has handled the entire * svndiff data set will result in @c SVN_ERR_SVNDIFF_UNEXPECTED_END, * else this error condition will be ignored. */ svn_stream_t * svn_txdelta_parse_svndiff(svn_txdelta_window_handler_t handler, void *handler_baton, svn_boolean_t error_on_early_close, apr_pool_t *pool); /** * Read and parse one delta window in svndiff format from the * readable stream @a stream and place it in @a *window, allocating * the result in @a pool. The caller must take responsibility for * stripping off the four-byte 'SVN@' header at the beginning of * the svndiff document before reading the first window, and must * provide the version number (the value of the fourth byte) to each * invocation of this routine with the @a svndiff_version argument. * * @since New in 1.1. */ svn_error_t * svn_txdelta_read_svndiff_window(svn_txdelta_window_t **window, svn_stream_t *stream, int svndiff_version, apr_pool_t *pool); /** * Read and skip one delta window in svndiff format from the * file @a file. @a pool is used for temporary allocations. The * caller must take responsibility for stripping off the four-byte * 'SVN@' header at the beginning of the svndiff document before * reading or skipping the first window, and must provide the version * number (the value of the fourth byte) to each invocation of this * routine with the @a svndiff_version argument. * * @since New in 1.1. */ svn_error_t * svn_txdelta_skip_svndiff_window(apr_file_t *file, int svndiff_version, apr_pool_t *pool); /** @} */ /** Traversing tree deltas. * * In Subversion, we've got various producers and consumers of tree * deltas. * * In processing a `commit' command: * - The client examines its working copy data, and produces a tree * delta describing the changes to be committed. * - The client networking library consumes that delta, and sends them * across the wire as an equivalent series of network requests (for * example, to svnserve as an ra_svn protocol stream, or to an * Apache httpd server as WebDAV commands) * - The server receives those requests and produces a tree delta --- * hopefully equivalent to the one the client produced above. * - The Subversion server module consumes that delta and commits an * appropriate transaction to the filesystem. * * In processing an `update' command, the process is reversed: * - The Subversion server module talks to the filesystem and produces * a tree delta describing the changes necessary to bring the * client's working copy up to date. * - The server consumes this delta, and assembles a reply * representing the appropriate changes. * - The client networking library receives that reply, and produces a * tree delta --- hopefully equivalent to the one the Subversion * server produced above. * - The working copy library consumes that delta, and makes the * appropriate changes to the working copy. * * The simplest approach would be to represent tree deltas using the * obvious data structure. To do an update, the server would * construct a delta structure, and the working copy library would * apply that structure to the working copy; the network layer's job * would simply be to get the structure across the net intact. * * However, we expect that these deltas will occasionally be too large * to fit in a typical workstation's swap area. For example, in * checking out a 200Mb source tree, the entire source tree is * represented by a single tree delta. So it's important to handle * deltas that are too large to fit in swap all at once. * * So instead of representing the tree delta explicitly, we define a * standard way for a consumer to process each piece of a tree delta * as soon as the producer creates it. The @c svn_delta_editor_t * structure is a set of callback functions to be defined by a delta * consumer, and invoked by a delta producer. Each invocation of a * callback function describes a piece of the delta --- a file's * contents changing, something being renamed, etc. * * @defgroup svn_delta_tree_deltas Tree deltas * @{ */ /** A structure full of callback functions the delta source will invoke * as it produces the delta. * * Note: Don't try to allocate one of these yourself. Instead, always * use svn_delta_default_editor() or some other constructor, to ensure * that unused slots are filled in with no-op functions. * *

Function Usage

* * Here's how to use these functions to express a tree delta. * * The delta consumer implements the callback functions described in * this structure, and the delta producer invokes them. So the * caller (producer) is pushing tree delta data at the callee * (consumer). * * At the start of traversal, the consumer provides @a edit_baton, a * baton global to the entire delta edit. If there is a target * revision that needs to be set for this operation, the producer * should call the @c set_target_revision function at this point. * * Next, if there are any tree deltas to express, the producer should * pass the @a edit_baton to the @c open_root function, to get a baton * representing root of the tree being edited. * * Most of the callbacks work in the obvious way: * * @c delete_entry * @c add_file * @c add_directory * @c open_file * @c open_directory * * Each of these takes a directory baton, indicating the directory * in which the change takes place, and a @a path argument, giving the * path (relative to the root of the edit) of the file, * subdirectory, or directory entry to change. Editors will usually * want to join this relative path with some base stored in the edit * baton (e.g. a URL, a location in the OS filesystem). * * Since every call requires a parent directory baton, including * @c add_directory and @c open_directory, where do we ever get our * initial directory baton, to get things started? The @c open_root * function returns a baton for the top directory of the change. In * general, the producer needs to invoke the editor's @c open_root * function before it can get anything of interest done. * * While @c open_root provides a directory baton for the root of * the tree being changed, the @c add_directory and @c open_directory * callbacks provide batons for other directories. Like the * callbacks above, they take a @a parent_baton and a relative path * @a path, and then return a new baton for the subdirectory being * created / modified --- @a child_baton. The producer can then use * @a child_baton to make further changes in that subdirectory. * * So, if we already have subdirectories named `foo' and `foo/bar', * then the producer can create a new file named `foo/bar/baz.c' by * calling: * * - @c open_root () --- yielding a baton @a root for the top directory * * - @c open_directory (@a root, "foo") --- yielding a baton @a f for `foo' * * - @c open_directory (@a f, "foo/bar") --- yielding a baton @a b for * `foo/bar' * * - @c add_file (@a b, "foo/bar/baz.c") * * When the producer is finished making changes to a directory, it * should call @c close_directory. This lets the consumer do any * necessary cleanup, and free the baton's storage. * * The @c add_file and @c open_file callbacks each return a baton * for the file being created or changed. This baton can then be * passed to @c apply_textdelta to change the file's contents, or * @c change_file_prop to change the file's properties. When the * producer is finished making changes to a file, it should call * @c close_file, to let the consumer clean up and free the baton. * * The @c add_file and @c add_directory functions each take arguments * @a copyfrom_path and @a copyfrom_revision. If @a copyfrom_path is * non-@c NULL, then @a copyfrom_path and @a copyfrom_revision indicate where * the file or directory should be copied from (to create the file * or directory being added). In that case, @a copyfrom_path must be * either a path relative to the root of the edit, or a URI from the * repository being edited. If @a copyfrom_path is @c NULL, then @a * copyfrom_revision must be @c SVN_INVALID_REVNUM; it is invalid to * pass a mix of valid and invalid copyfrom arguments. * * *

Function Call Ordering

* * There are six restrictions on the order in which the producer * may use the batons: * * 1. The producer may call @c open_directory, @c add_directory, * @c open_file, @c add_file at most once on any given directory * entry. @c delete_entry may be called at most once on any given * directory entry and may later be followed by @c add_directory or * @c add_file on the same directory entry. @c delete_entry may * not be called on any directory entry after @c open_directory, * @c add_directory, @c open_file or @c add_file has been called on * that directory entry. * * 2. The producer may not close a directory baton until it has * closed all batons for its subdirectories. * * 3. When a producer calls @c open_directory or @c add_directory, * it must specify the most recently opened of the currently open * directory batons. Put another way, the producer cannot have * two sibling directory batons open at the same time. * * 4. A producer must call @c change_dir_prop on a directory either * before opening any of the directory's subdirs or after closing * them, but not in the middle. * * 5. When the producer calls @c open_file or @c add_file, either: * * (a) The producer must follow with any changes to the file * (@c change_file_prop and/or @c apply_textdelta, as applicable), * followed by a @c close_file call, before issuing any other file * or directory calls, or * * (b) The producer must follow with a @c change_file_prop call if * it is applicable, before issuing any other file or directory * calls; later, after all directory batons including the root * have been closed, the producer must issue @c apply_textdelta * and @c close_file calls. * * 6. When the producer calls @c apply_textdelta, it must make all of * the window handler calls (including the @c NULL window at the * end) before issuing any other @c svn_delta_editor_t calls. * * So, the producer needs to use directory and file batons as if it * is doing a single depth-first traversal of the tree, with the * exception that the producer may keep file batons open in order to * make @c apply_textdelta calls at the end. * * *

Pool Usage

* * Many editor functions are invoked multiple times, in a sequence * determined by the editor "driver". The driver is responsible for * creating a pool for use on each iteration of the editor function, * and clearing that pool between each iteration. The driver passes * the appropriate pool on each function invocation. * * Based on the requirement of calling the editor functions in a * depth-first style, it is usually customary for the driver to similarly * nest the pools. However, this is only a safety feature to ensure * that pools associated with deeper items are always cleared when the * top-level items are also cleared. The interface does not assume, nor * require, any particular organization of the pools passed to these * functions. In fact, if "postfix deltas" are used for files, the file * pools definitely need to live outside the scope of their parent * directories' pools. * * Note that close_directory can be called *before* a file in that * directory has been closed. That is, the directory's baton is * closed before the file's baton. The implication is that * @c apply_textdelta and @c close_file should not refer to a parent * directory baton UNLESS the editor has taken precautions to * allocate it in a pool of the appropriate lifetime (the @a dir_pool * passed to @c open_directory and @c add_directory definitely does not * have the proper lifetime). In general, it is recommended to simply * avoid keeping a parent directory baton in a file baton. * * *

Errors

* * At least one implementation of the editor interface is * asynchronous; an error from one operation may be detected some * number of operations later. As a result, an editor driver must not * assume that an error from an editing function resulted from the * particular operation being detected. Moreover, once an editing * function returns an error, the edit is dead; the only further * operation which may be called on the editor is abort_edit. */ typedef struct svn_delta_editor_t { /** Set the target revision for this edit to @a target_revision. This * call, if used, should precede all other editor calls. * * @note This is typically used only for server->client update-type * operations. It doesn't really make much sense for commit-type * operations, because the revision of a commit isn't known until * the commit is finalized. */ svn_error_t *(*set_target_revision)(void *edit_baton, svn_revnum_t target_revision, apr_pool_t *pool); /** Set @a *root_baton to a baton for the top directory of the change. * (This is the top of the subtree being changed, not necessarily * the root of the filesystem.) As with any other directory baton, the * producer should call @c close_directory on @a root_baton when done. * And as with other @c open_* calls, the @a base_revision here is the * current revision of the directory (before getting bumped up to the * new target revision set with @c set_target_revision). * * Allocations for the returned @a root_baton should be performed in * @a dir_pool. It is also typical to (possibly) save this pool for later * usage by @c close_directory. */ svn_error_t *(*open_root)(void *edit_baton, svn_revnum_t base_revision, apr_pool_t *dir_pool, void **root_baton); /** Remove the directory entry named @a path, a child of the directory * represented by @a parent_baton. If @a revision is a valid * revision number, it is used as a sanity check to ensure that you * are really removing the revision of @a path that you think you are. * * All allocations should be performed in @a pool. * * @note The @a revision parameter is typically used only for * client->server commit-type operations, allowing the server to * verify that it is deleting what the client thinks it should be * deleting. It only really makes sense in the opposite direction * (during server->client update-type operations) when the trees * whose delta is being described are ancestrally related (that is, * one tree is an ancestor of the other). */ svn_error_t *(*delete_entry)(const char *path, svn_revnum_t revision, void *parent_baton, apr_pool_t *pool); /** We are going to add a new subdirectory named @a path. We will use * the value this callback stores in @a *child_baton as the * @a parent_baton for further changes in the new subdirectory. * * If @a copyfrom_path is non-@c NULL, this add has history (i.e., is a * copy), and the origin of the copy may be recorded as * @a copyfrom_path under @a copyfrom_revision. * * Allocations for the returned @a child_baton should be performed in * @a dir_pool. It is also typical to (possibly) save this pool for later * usage by @c close_directory. */ svn_error_t *(*add_directory)(const char *path, void *parent_baton, const char *copyfrom_path, svn_revnum_t copyfrom_revision, apr_pool_t *dir_pool, void **child_baton); /** We are going to make changes in a subdirectory (of the directory * identified by @a parent_baton). The subdirectory is specified by * @a path. The callback must store a value in @a *child_baton that * should be used as the @a parent_baton for subsequent changes in this * subdirectory. If a valid revnum, @a base_revision is the current * revision of the subdirectory. * * Allocations for the returned @a child_baton should be performed in * @a dir_pool. It is also typical to (possibly) save this pool for later * usage by @c close_directory. */ svn_error_t *(*open_directory)(const char *path, void *parent_baton, svn_revnum_t base_revision, apr_pool_t *dir_pool, void **child_baton); /** Change the value of a directory's property. * - @a dir_baton specifies the directory whose property should change. * - @a name is the name of the property to change. * - @a value is the new (final) value of the property, or @c NULL if the * property should be removed altogether. * * The callback is guaranteed to be called exactly once for each property * whose value differs between the start and the end of the edit. * * All allocations should be performed in @a pool. */ svn_error_t *(*change_dir_prop)(void *dir_baton, const char *name, const svn_string_t *value, apr_pool_t *pool); /** We are done processing a subdirectory, whose baton is @a dir_baton * (set by @c add_directory or @c open_directory). We won't be using * the baton any more, so whatever resources it refers to may now be * freed. */ svn_error_t *(*close_directory)(void *dir_baton, apr_pool_t *pool); /** In the directory represented by @a parent_baton, indicate that * @a path is present as a subdirectory in the edit source, but * cannot be conveyed to the edit consumer (perhaps because of * authorization restrictions). */ svn_error_t *(*absent_directory)(const char *path, void *parent_baton, apr_pool_t *pool); /** We are going to add a new file named @a path. The callback can * store a baton for this new file in @a **file_baton; whatever value * it stores there should be passed through to @c apply_textdelta. * * If @a copyfrom_path is non-@c NULL, this add has history (i.e., is a * copy), and the origin of the copy may be recorded as * @a copyfrom_path under @a copyfrom_revision. * * Allocations for the returned @a file_baton should be performed in * @a file_pool. It is also typical to save this pool for later usage * by @c apply_textdelta and possibly @c close_file. */ svn_error_t *(*add_file)(const char *path, void *parent_baton, const char *copyfrom_path, svn_revnum_t copyfrom_revision, apr_pool_t *file_pool, void **file_baton); /** We are going to make change to a file named @a path, which resides * in the directory identified by @a parent_baton. * * The callback can store a baton for this new file in @a **file_baton; * whatever value it stores there should be passed through to * @c apply_textdelta. If a valid revnum, @a base_revision is the * current revision of the file. * * Allocations for the returned @a file_baton should be performed in * @a file_pool. It is also typical to save this pool for later usage * by @c apply_textdelta and possibly @c close_file. */ svn_error_t *(*open_file)(const char *path, void *parent_baton, svn_revnum_t base_revision, apr_pool_t *file_pool, void **file_baton); /** Apply a text delta, yielding the new revision of a file. * * @a file_baton indicates the file we're creating or updating, and the * ancestor file on which it is based; it is the baton set by some * prior @c add_file or @c open_file callback. * * The callback should set @a *handler to a text delta window * handler; we will then call @a *handler on successive text * delta windows as we receive them. The callback should set * @a *handler_baton to the value we should pass as the @a baton * argument to @a *handler. * * @a base_checksum is the hex MD5 digest for the base text against * which the delta is being applied; it is ignored if NULL, and may * be ignored even if not NULL. If it is not ignored, it must match * the checksum of the base text against which svndiff data is being * applied; if it does not, @c apply_textdelta or the @a *handler call * which detects the mismatch will return the error * SVN_ERR_CHECKSUM_MISMATCH (if there is no base text, there may * still be an error if @a base_checksum is neither NULL nor the hex * MD5 checksum of the empty string). */ svn_error_t *(*apply_textdelta)(void *file_baton, const char *base_checksum, apr_pool_t *pool, svn_txdelta_window_handler_t *handler, void **handler_baton); /** Change the value of a file's property. * - @a file_baton specifies the file whose property should change. * - @a name is the name of the property to change. * - @a value is the new (final) value of the property, or @c NULL if the * property should be removed altogether. * * The callback is guaranteed to be called exactly once for each property * whose value differs between the start and the end of the edit. * * All allocations should be performed in @a pool. */ svn_error_t *(*change_file_prop)(void *file_baton, const char *name, const svn_string_t *value, apr_pool_t *pool); /** We are done processing a file, whose baton is @a file_baton (set by * @c add_file or @c open_file). We won't be using the baton any * more, so whatever resources it refers to may now be freed. * * @a text_checksum is the hex MD5 digest for the fulltext that * resulted from a delta application, see @c apply_textdelta. The * checksum is ignored if NULL. If not null, it is compared to the * checksum of the new fulltext, and the error * SVN_ERR_CHECKSUM_MISMATCH is returned if they do not match. If * there is no new fulltext, @a text_checksum is ignored. */ svn_error_t *(*close_file)(void *file_baton, const char *text_checksum, apr_pool_t *pool); /** In the directory represented by @a parent_baton, indicate that * @a path is present as a file in the edit source, but cannot be * conveyed to the edit consumer (perhaps because of authorization * restrictions). */ svn_error_t *(*absent_file)(const char *path, void *parent_baton, apr_pool_t *pool); /** All delta processing is done. Call this, with the @a edit_baton for * the entire edit. */ svn_error_t *(*close_edit)(void *edit_baton, apr_pool_t *pool); /** The editor-driver has decided to bail out. Allow the editor to * gracefully clean up things if it needs to. */ svn_error_t *(*abort_edit)(void *edit_baton, apr_pool_t *pool); /* Be sure to update svn_delta_get_cancellation_editor() and * svn_delta_default_editor() if you add a new callback here. */ } svn_delta_editor_t; /** Return a default delta editor template, allocated in @a pool. * * The editor functions in the template do only the most basic * baton-swapping: each editor function that produces a baton does so * by copying its incoming baton into the outgoing baton reference. * * This editor is not intended to be useful by itself, but is meant to * be the basis for a useful editor. After getting a default editor, * you substitute in your own implementations for the editor functions * you care about. The ones you don't care about, you don't have to * implement -- you can rely on the template's implementation to * safely do nothing of consequence. */ svn_delta_editor_t * svn_delta_default_editor(apr_pool_t *pool); /** A text-delta window handler which does nothing. * * Editors can return this handler from @c apply_textdelta if they don't * care about text delta windows. */ svn_error_t * svn_delta_noop_window_handler(svn_txdelta_window_t *window, void *baton); /** Set @a *editor and @a *edit_baton to a cancellation editor that * wraps @a wrapped_editor and @a wrapped_baton. * * The @a editor will call @a cancel_func with @a cancel_baton when each of * its functions is called, continuing on to call the corresponding wrapped * function if @a cancel_func returns @c SVN_NO_ERROR. * * If @a cancel_func is @c NULL, set @a *editor to @a wrapped_editor and * @a *edit_baton to @a wrapped_baton. */ svn_error_t * svn_delta_get_cancellation_editor(svn_cancel_func_t cancel_func, void *cancel_baton, const svn_delta_editor_t *wrapped_editor, void *wrapped_baton, const svn_delta_editor_t **editor, void **edit_baton, apr_pool_t *pool); /** Set @a *editor and @a *edit_baton to an depth-based filtering * editor that wraps @a wrapped_editor and @a wrapped_baton. * * The @a editor will track the depth of this drive against the @a * requested_depth, taking into account whether not the edit drive is * making use of a target (via @a has_target), and forward editor * calls which operate "within" the request depth range through to @a * wrapped_editor. * * @a requested_depth must be one of the following depth values: * @c svn_depth_infinity, @c svn_depth_empty, @c svn_depth_files, * @c svn_depth_immediates, or @c svn_depth_unknown. * * If filtering is deemed unncessary (or if @a requested_depth is @c * svn_depth_unknown), @a *editor and @a *edit_baton will be set to @a * wrapped_editor and @a wrapped_baton, respectively; otherwise, * they'll be set to new objects allocated from @a pool. * * @note Because the svn_delta_editor_t interface's @c delete_entry() * function doesn't carry node kind information, a depth-based * filtering editor being asked to filter for @c svn_depth_files but * receiving a @c delete_entry() call on an immediate child of the * editor's target is unable to know if that deletion should be * allowed or filtered out -- a delete of a top-level file is okay in * this case, a delete of a top-level subdirectory is not. As such, * this filtering editor takes a conservative approach, and ignores * top-level deletion requests when filtering for @c svn_depth_files. * Fortunately, most non-depth-aware (pre-1.5) Subversion editor * drivers can be told to drive non-recursively (where non-recursive * means essentially @c svn_depth_files), which means they won't * transmit out-of-scope editor commands anyway. * * @since New in 1.5. */ svn_error_t * svn_delta_depth_filter_editor(const svn_delta_editor_t **editor, void **edit_baton, const svn_delta_editor_t *wrapped_editor, void *wrapped_edit_baton, svn_depth_t requested_depth, svn_boolean_t has_target, apr_pool_t *pool); /** @} */ /** Path-based editor drives. * * @defgroup svn_delta_path_delta_drivers Path-based delta drivers * @{ */ /** Callback function type for svn_delta_path_driver(). * * The handler of this callback is given the callback baton @a * callback_baton, @a path, and the @a parent_baton which represents * path's parent directory as created by the editor passed to * svn_delta_path_driver(). * * If @a path represents a directory, the handler must return a @a * *dir_baton for @a path, generated from the same editor (so that the * driver can later close that directory). * * If, however, @a path represents a file, the handler should NOT * return any file batons. It can close any opened or added files * immediately, or delay that close until the end of the edit when * svn_delta_path_driver() returns. * * Finally, if @a parent_baton is @c NULL, then the root of the edit * is also one of the paths passed to svn_delta_path_driver(). The * handler of this callback must call the editor's open_root() * function and return the top-level root dir baton in @a *dir_baton. */ typedef svn_error_t *(*svn_delta_path_driver_cb_func_t) (void **dir_baton, void *parent_baton, void *callback_baton, const char *path, apr_pool_t *pool); /** Drive @a editor (with its @a edit_baton) in such a way that * each path in @a paths is traversed in a depth-first fashion. As * each path is hit as part of the editor drive, use @a * callback_func and @a callback_baton to allow the caller to handle * the portion of the editor drive related to that path. * * Use @a revision as the revision number passed to intermediate * directory openings. * * Use @a pool for all necessary allocations. */ svn_error_t * svn_delta_path_driver(const svn_delta_editor_t *editor, void *edit_baton, svn_revnum_t revision, apr_array_header_t *paths, svn_delta_path_driver_cb_func_t callback_func, void *callback_baton, apr_pool_t *pool); /** @} */ /*** File revision iterator types ***/ /** * The callback invoked by file rev loopers, such as * svn_ra_plugin_t.get_file_revs2() and svn_repos_get_file_revs2(). * * @a baton is provided by the caller, @a path is the pathname of the file * in revision @a rev and @a rev_props are the revision properties. * * If @a delta_handler and @a delta_baton are non-NULL, they may be set to a * handler/baton which will be called with the delta between the previous * revision and this one after the return of this callback. They may be * left as NULL/NULL. * * @a result_of_merge will be @c TRUE if the revision being returned was * included as the result of a merge. * * @a prop_diffs is an array of svn_prop_t elements indicating the property * delta for this and the previous revision. * * @a pool may be used for temporary allocations, but you can't rely * on objects allocated to live outside of this particular call and * the immediately following calls to @a *delta_handler if any. (Pass * in a pool via @a baton if need be.) * * @since New in 1.5. */ typedef svn_error_t *(*svn_file_rev_handler_t) (void *baton, const char *path, svn_revnum_t rev, apr_hash_t *rev_props, svn_boolean_t result_of_merge, svn_txdelta_window_handler_t *delta_handler, void **delta_baton, apr_array_header_t *prop_diffs, apr_pool_t *pool); /** * The old file rev handler interface. * * @note @c svn_file_rev_handler_old_t is a placeholder type for both * @c svn_repos_file_rev_handler_t and @c svn_ra_file_rev_handler_t. It is * reproduced here for dependency reasons. * * @deprecated This type is provided for the svn_compat_wrap_file_rev_handler() * compatibilty wrapper, and should not be used for new development. * @since New in 1.5. */ typedef svn_error_t *(*svn_file_rev_handler_old_t) (void *baton, const char *path, svn_revnum_t rev, apr_hash_t *rev_props, svn_txdelta_window_handler_t *delta_handler, void **delta_baton, apr_array_header_t *prop_diffs, apr_pool_t *pool); /** Return, in @a *handler2 and @a *handler2_baton a function/baton that * will call @a handler/@a handler_baton, allocating the @a *handler2_baton * in @a pool. * * @note This is used by compatibility wrappers, which exist in more than * Subversion core library. * * @note @c svn_file_rev_handler_old_t is a placeholder type for both * @c svn_repos_file_rev_handler_t and @c svn_ra_file_rev_handler_t. It is * reproduced here for dependency reasons. * * @since New in 1.5. */ void svn_compat_wrap_file_rev_handler(svn_file_rev_handler_t *handler2, void **handler2_baton, svn_file_rev_handler_old_t handler, void *handler_baton, apr_pool_t *pool); /** @} end group: delta_support */ #ifdef __cplusplus } #endif /* __cplusplus */ #endif /* SVN_DELTA_H */