1 files changed, 142 insertions, 0 deletions
diff --git a/include/git2/filter.h b/include/git2/filter.h
new file mode 100644
index 000000000..f96b6766b
--- /dev/null
+++ b/include/git2/filter.h
@@ -0,0 +1,142 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_filter_h__
+#define INCLUDE_git_filter_h__
+
+#include "common.h"
+#include "types.h"
+#include "oid.h"
+#include "buffer.h"
+
+/**
+ * @file git2/filter.h
+ * @brief Git filter APIs
+ *
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Filters are applied in one of two directions: smudging - which is
+ * exporting a file from the Git object database to the working directory,
+ * and cleaning - which is importing a file from the working directory to
+ * the Git object database.  These values control which direction of
+ * change is being applied.
+ */
+typedef enum {
+	GIT_FILTER_TO_WORKTREE = 0,
+	GIT_FILTER_SMUDGE = GIT_FILTER_TO_WORKTREE,
+	GIT_FILTER_TO_ODB = 1,
+	GIT_FILTER_CLEAN = GIT_FILTER_TO_ODB,
+} git_filter_mode_t;
+
+/**
+ * A filter that can transform file data
+ *
+ * This represents a filter that can be used to transform or even replace
+ * file data.  Libgit2 includes one built in filter and it is possible to
+ * write your own (see git2/sys/filter.h for information on that).
+ *
+ * The two builtin filters are:
+ *
+ * * "crlf" which uses the complex rules with the "text", "eol", and
+ *   "crlf" file attributes to decide how to convert between LF and CRLF
+ *   line endings
+ * * "ident" which replaces "$Id$" in a blob with "$Id: <blob OID>$" upon
+ *   checkout and replaced "$Id: <anything>$" with "$Id$" on checkin.
+ */
+typedef struct git_filter git_filter;
+
+/**
+ * List of filters to be applied
+ *
+ * This represents a list of filters to be applied to a file / blob.  You
+ * can build the list with one call, apply it with another, and dispose it
+ * with a third.  In typical usage, there are not many occasions where a
+ * git_filter_list is needed directly since the library will generally
+ * handle conversions for you, but it can be convenient to be able to
+ * build and apply the list sometimes.
+ */
+typedef struct git_filter_list git_filter_list;
+
+/**
+ * Load the filter list for a given path.
+ *
+ * This will return 0 (success) but set the output git_filter_list to NULL
+ * if no filters are requested for the given file.
+ *
+ * @param filters Output newly created git_filter_list (or NULL)
+ * @param repo Repository object that contains `path`
+ * @param blob The blob to which the filter will be applied (if known)
+ * @param path Relative path of the file to be filtered
+ * @param mode Filtering direction (WT->ODB or ODB->WT)
+ * @return 0 on success (which could still return NULL if no filters are
+ *         needed for the requested file), <0 on error
+ */
+GIT_EXTERN(int) git_filter_list_load(
+	git_filter_list **filters,
+	git_repository *repo,
+	git_blob *blob, /* can be NULL */
+	const char *path,
+	git_filter_mode_t mode);
+
+/**
+ * Apply filter list to a data buffer.
+ *
+ * See `git2/buffer.h` for background on `git_buf` objects.
+ *
+ * If the `in` buffer holds data allocated by libgit2 (i.e. `in->asize` is
+ * not zero), then it will be overwritten when applying the filters.  If
+ * not, then it will be left untouched.
+ *
+ * If there are no filters to apply (or `filters` is NULL), then the `out`
+ * buffer will reference the `in` buffer data (with `asize` set to zero)
+ * instead of allocating data.  This keeps allocations to a minimum, but
+ * it means you have to be careful about freeing the `in` data since `out`
+ * may be pointing to it!
+ *
+ * @param out Buffer to store the result of the filtering
+ * @param filters A loaded git_filter_list (or NULL)
+ * @param in Buffer containing the data to filter
+ * @return 0 on success, an error code otherwise
+ */
+GIT_EXTERN(int) git_filter_list_apply_to_data(
+	git_buf *out,
+	git_filter_list *filters,
+	git_buf *in);
+
+/**
+ * Apply filter list to the contents of a file on disk
+ */
+GIT_EXTERN(int) git_filter_list_apply_to_file(
+	git_buf *out,
+	git_filter_list *filters,
+	git_repository *repo,
+	const char *path);
+
+/**
+ * Apply filter list to the contents of a blob
+ */
+GIT_EXTERN(int) git_filter_list_apply_to_blob(
+	git_buf *out,
+	git_filter_list *filters,
+	git_blob *blob);
+
+/**
+ * Free a git_filter_list
+ *
+ * @param filters A git_filter_list created by `git_filter_list_load`
+ */
+GIT_EXTERN(void) git_filter_list_free(git_filter_list *filters);
+
+
+GIT_END_DECL
+
+/** @} */
+
+#endif