Create public filter object and use it

This creates include/sys/filter.h with a basic definition of a
git_filter and then converts the internal code to use it.  There
are related internal objects (git_filter_list) that we will want
to publish at some point, but this is a first step.

1 files changed, 29 insertions, 32 deletions

diff --git a/src/filter.h b/src/filter.h
index 67845ad6a..a4ee2172d 100644
--- a/src/filter.h
+++ b/src/filter.h
@@ -9,14 +9,11 @@
 
 #include "common.h"
 #include "buffer.h"
+#include "array.h"
 #include "git2/odb.h"
 #include "git2/repository.h"
 #include "git2/filter.h"
-
-struct git_filter {
-	int (*apply)(struct git_filter *self, git_buf *dest, const git_buf *source);
-	void (*do_free)(struct git_filter *self);
-};
+#include "git2/sys/filter.h"
 
 typedef enum {
 	GIT_CRLF_GUESS = -1,
@@ -27,34 +24,38 @@ typedef enum {
 	GIT_CRLF_AUTO,
 } git_crlf_t;
 
+typedef struct git_filter_list git_filter_list;
+
 /*
  * FILTER API
  */
 
 /*
- * For any given path in the working directory, fill the `filters`
- * array with the relevant filters that need to be applied.
+ * For any given path in the working directory, create a `git_filter_list`
+ * with the relevant filters that need to be applied.
  *
- * Mode is either `GIT_FILTER_TO_WORKTREE` if you need to load the
- * filters that will be used when checking out a file to the working
- * directory, or `GIT_FILTER_TO_ODB` for the filters used when writing
- * a file to the ODB.
+ * 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 Vector where to store all the loaded filters
+ * @param filters Output newly created git_filter_list (or NULL)
  * @param repo Repository object that contains `path`
  * @param path Relative path of the file to be filtered
  * @param mode Filtering direction (WT->ODB or ODB->WT)
- * @return the number of filters loaded for the file (0 if the file
- *	doesn't need filtering), or a negative error code
+ * @return 0 on success (which could still return NULL if no filters are
+ *         needed for the requested file), <0 on error
  */
-extern int git_filters_load(git_vector *filters, git_repository *repo, const char *path, int mode);
+extern int git_filter_list_load(
+	git_filter_list **filters,
+	git_repository *repo,
+	const char *path,
+	git_filter_mode_t mode);
 
 /*
- * Apply one or more filters to a file.
+ * Apply one or more filters to a data buffer.
  *
- * The file must have been loaded as a `git_buf` object. Both the `source`
- * and `dest` buffers are owned by the caller and must be freed once
- * they are no longer needed.
+ * The source data must have been loaded as a `git_buf` object. Both the
+ * `source` and `dest` buffers are owned by the caller and must be freed
+ * once they are no longer needed.
  *
  * NOTE: Because of the double-buffering schema, the `source` buffer that
  * contains the original file may be tampered once the filtering is
@@ -63,29 +64,25 @@ extern int git_filters_load(git_vector *filters, git_repository *repo, const cha
  *
  * @param dest Buffer to store the result of the filtering
  * @param source Buffer containing the document to filter
- * @param filters Vector of filters as supplied by `git_filters_load`
+ * @param filters An already loaded git_filter_list
  * @return 0 on success, an error code otherwise
  */
-extern int git_filters_apply(git_buf *dest, git_buf *source, git_vector *filters);
+extern int git_filter_list_apply(
+	git_buf *dest,
+	git_buf *source,
+	git_filter_list *filters);
 
 /*
- * Free the `filters` array generated by `git_filters_load`.
+ * Free the git_filter_list
  *
- * Note that this frees both the array and its contents. The array will
- * be clean/reusable after this call.
- *
- * @param filters A filters array as supplied by `git_filters_load`
+ * @param filters A git_filter_list created by `git_filter_list_load`
  */
-extern void git_filters_free(git_vector *filters);
+extern void git_filter_list_free(git_filter_list *filters);
 
 /*
  * Available filters
  */
 
-/* Strip CRLF, from Worktree to ODB */
-extern int git_filter_add__crlf_to_odb(git_vector *filters, git_repository *repo, const char *path);
-
-/* Add CRLF, from ODB to worktree */
-extern int git_filter_add__crlf_to_workdir(git_vector *filters, git_repository *repo, const char *path);
+extern git_filter *git_crlf_filter_new(void);
 
 #endif