1 files changed, 43 insertions, 4 deletions
diff --git a/include/git2/userbuf.h b/include/git2/userbuf.h
index 4fe8ccf47..2e498914a 100644
--- a/include/git2/userbuf.h
+++ b/include/git2/userbuf.h
@@ -28,9 +28,9 @@ GIT_BEGIN_DECL
  * A data buffer for exporting data from libgit2.
  *
  * Sometimes libgit2 wants to return an allocated data buffer to the
- * caller and have the caller take responsibility for freeing that memory.
- * This structure should be freed with `git_userbuf_dispose` when you
- * have finished with it.
+ * caller and allow the caller take responsibility for its lifecycle.
+ * This requires the caller to free the memory with `git_userbuf_dispose`
+ * when they have finished using it.
  */
 typedef struct {
 	/**
@@ -54,6 +54,22 @@ typedef struct {
 } git_userbuf;
 
 /**
+ * Check quickly if buffer looks like it contains binary data
+ *
+ * @param buf Buffer to check
+ * @return 1 if buffer looks like non-text data
+ */
+GIT_EXTERN(int) git_userbuf_is_binary(const git_userbuf *buf);
+
+ /**
+ * Check quickly if buffer contains a NUL byte
+ *
+ * @param buf Buffer to check
+ * @return 1 if buffer contains a NUL byte
+ */
+GIT_EXTERN(int) git_userbuf_contains_nul(const git_userbuf *buf);
+
+/**
  * Places the given data in the buffer.  This is necessary for some
  * callback functions that take user data.  If there is already data in
  * the buffer, you should call `git_userbuf_dispose` before setting the
@@ -63,7 +79,30 @@ typedef struct {
  * @param ptr The data to place in the buffer
  * @param len The length of the data in bytes
  */
-GIT_EXTERN(int) git_userbuf_set(git_userbuf *buf, const char *ptr, size_t len);
+GIT_EXTERN(int) git_userbuf_set(git_userbuf *buf, const void *ptr, size_t len);
+
+/**
+ * Resize the buffer allocation to make more space.
+ *
+ * This will attempt to grow the buffer to accommodate the target size.
+ *
+ * If the buffer refers to memory that was not allocated by libgit2 (i.e.
+ * the `asize` field is zero), then `ptr` will be replaced with a newly
+ * allocated block of data.  Be careful so that memory allocated by the
+ * caller is not lost.  As a special variant, if you pass `target_size` as
+ * 0 and the memory is not allocated by libgit2, this will allocate a new
+ * buffer of size `size` and copy the external data into it.
+ *
+ * Currently, this will never shrink a buffer, only expand it.
+ *
+ * If the allocation fails, this will return an error and the buffer will be
+ * marked as invalid for future operations, invaliding the contents.
+ *
+ * @param buffer The buffer to be resized; may or may not be allocated yet
+ * @param target_size The desired available size
+ * @return 0 on success, -1 on allocation failure
+ */
+GIT_EXTERN(int) git_userbuf_grow(git_userbuf *buffer, size_t target_size);
 
 /**
  * Free the memory referred to by the git_userbuf.