argv-array: move doc to argv-array.h

[thirdparty/git.git] / diffcore.h

diff --git a/diffcore.h b/diffcore.h
index 8d81a45f510c0aed0cafcd3dce638f18fc6566f7..7c07347e42b52c0d010b0c13011536afc0c4d581 100644 (file)
--- a/diffcore.h
+++ b/diffcore.h
@@ -7,6 +7,8 @@
 #include "cache.h"
 
 struct diff_options;
+struct repository;
+struct userdiff_driver;
 
 /* This header file is internal between diff.c and its diff transformers
  * (e.g. diffcore-rename, diffcore-pickaxe).  Never include this header
@@ -26,8 +28,12 @@ struct diff_options;
 
 #define MINIMUM_BREAK_SIZE     400 /* do not break a file smaller than this */
 
-struct userdiff_driver;
-
+/**
+ * the internal representation for a single file (blob).  It records the blob
+ * object name (if known -- for a work tree file it typically is a NUL SHA-1),
+ * filemode and pathname.  This is what the `diff_addremove()`, `diff_change()`
+ * and `diff_unmerge()` synthesize and feed `diff_queue()` function with.
+ */
 struct diff_filespec {
        struct object_id oid;
        char *path;
@@ -61,11 +67,22 @@ void fill_filespec(struct diff_filespec *, const struct object_id *,
 
 #define CHECK_SIZE_ONLY 1
 #define CHECK_BINARY    2
-int diff_populate_filespec(struct diff_filespec *, unsigned int);
+int diff_populate_filespec(struct repository *, struct diff_filespec *, unsigned int);
 void diff_free_filespec_data(struct diff_filespec *);
 void diff_free_filespec_blob(struct diff_filespec *);
-int diff_filespec_is_binary(struct diff_filespec *);
-
+int diff_filespec_is_binary(struct repository *, struct diff_filespec *);
+
+/**
+ * This records a pair of `struct diff_filespec`; the filespec for a file in
+ * the "old" set (i.e. preimage) is called `one`, and the filespec for a file
+ * in the "new" set (i.e. postimage) is called `two`.  A change that represents
+ * file creation has NULL in `one`, and file deletion has NULL in `two`.
+ *
+ * A `filepair` starts pointing at `one` and `two` that are from the same
+ * filename, but `diffcore_std()` can break pairs and match component filespecs
+ * with other filespecs from a different filepair to form new filepair. This is
+ * called 'rename detection'.
+ */
 struct diff_filepair {
        struct diff_filespec *one;
        struct diff_filespec *two;
@@ -77,6 +94,7 @@ struct diff_filepair {
        unsigned done_skip_stat_unmatch : 1;
        unsigned skip_stat_unmatch_result : 1;
 };
+
 #define DIFF_PAIR_UNMERGED(p) ((p)->is_unmerged)
 
 #define DIFF_PAIR_RENAME(p) ((p)->renamed_pair)
@@ -94,11 +112,25 @@ void diff_free_filepair(struct diff_filepair *);
 
 int diff_unmodified_pair(struct diff_filepair *);
 
+/**
+ * This is a collection of filepairs.  Notable members are:
+ *
+ * - `queue`:
+ * An array of pointers to `struct diff_filepair`. This dynamically grows as
+ * you add filepairs;
+ *
+ * - `alloc`:
+ * The allocated size of the `queue` array;
+ *
+ * - `nr`:
+ * The number of elements in the `queue` array.
+ */
 struct diff_queue_struct {
        struct diff_filepair **queue;
        int alloc;
        int nr;
 };
+
 #define DIFF_QUEUE_CLEAR(q) \
        do { \
                (q)->queue = NULL; \
@@ -111,7 +143,7 @@ struct diff_filepair *diff_queue(struct diff_queue_struct *,
                                 struct diff_filespec *);
 void diff_q(struct diff_queue_struct *, struct diff_filepair *);
 
-void diffcore_break(int);
+void diffcore_break(struct repository *, int);
 void diffcore_rename(struct diff_options *);
 void diffcore_merge_broken(void);
 void diffcore_pickaxe(struct diff_options *);
@@ -142,7 +174,8 @@ void diff_debug_queue(const char *, struct diff_queue_struct *);
 #define diff_debug_queue(a,b) do { /* nothing */ } while (0)
 #endif
 
-int diffcore_count_changes(struct diff_filespec *src,
+int diffcore_count_changes(struct repository *r,
+                          struct diff_filespec *src,
                           struct diff_filespec *dst,
                           void **src_count_p,
                           void **dst_count_p,