Major refactoring: upb_string is gone in favor of upb_strref.

1 files changed, 41 insertions, 13 deletions

diff --git a/src/upb_stdio.h b/src/upb_stdio.h
index a164821..858830c 100644
--- a/src/upb_stdio.h
+++ b/src/upb_stdio.h
@@ -5,7 +5,12 @@
  * Author: Josh Haberman <jhaberman@gmail.com>
  *
  * This file provides upb_bytesrc and upb_bytesink implementations for
- * ANSI C stdio.
+ * ANSI C stdio, which is less efficient than posixfd, but more portable.
+ *
+ * Specifically, stdio functions acquire locks on every operation (unless you
+ * use the f{read,write,...}_unlocked variants, which are not standard) and
+ * performs redundant buffering (unless you disable it with setvbuf(), but we
+ * can only do this on newly-opened filehandles).
  */
 
 #include <stdio.h>
@@ -18,21 +23,44 @@
 extern "C" {
 #endif
 
-struct upb_stdio;
-typedef struct upb_stdio upb_stdio;
+typedef struct {
+  uint64_t ofs;
+  uint32_t refcount;
+  char data[];
+} upb_stdio_buf;
+
+// We use a single object for both bytesrc and bytesink for simplicity.
+// The object is still not thread-safe, and may only be used by one reader
+// and one writer at a time.
+typedef struct {
+  upb_bytesrc src;
+  upb_bytesink sink;
+  FILE *file;
+  bool should_close;
+  upb_stdio_buf **bufs;
+  uint32_t nbuf, szbuf;
+} upb_stdio;
+
+void upb_stdio_init(upb_stdio *stdio);
+// Caller should call upb_stdio_flush prior to calling this to ensure that
+// all data is flushed, otherwise data can be silently dropped if an error
+// occurs flushing the remaining buffers.
+void upb_stdio_uninit(upb_stdio *stdio);
+
+// Resets the object to read/write to the given "file."  The caller is
+// responsible for closing the file, which must outlive this object.
+void upb_stdio_reset(upb_stdio *stdio, FILE *file);
 
-// Creation/deletion.
-upb_stdio *upb_stdio_new();
-void upb_stdio_free(upb_stdio *stdio);
+// As an alternative to upb_stdio_reset(), initializes the object by opening a
+// file, and will handle closing it.  This may result in more efficient I/O
+// than the previous since we can call setvbuf() to disable buffering.
+void upb_stdio_open(upb_stdio *stdio, const char *filename, const char *mode,
+                    upb_status *s);
 
-// Reset/initialize the object for use.  The src or sink will call
-// fread()/fwrite()/etc. on the given FILE*.
-void upb_stdio_reset(upb_stdio *stdio, FILE* file);
+// Must be called to cleanup after the object, including closing the file if
+// it was opened with upb_stdio_open() (which can fail, hence the status).
+//
 
-// Gets a bytesrc or bytesink for the given stdio.  The returned pointer is
-// invalidated by upb_stdio_reset above.  It is perfectly valid to get both
-// a bytesrc and a bytesink for the same stdio if the FILE* is open for reading
-// and writing.
 upb_bytesrc *upb_stdio_bytesrc(upb_stdio *stdio);
 upb_bytesink *upb_stdio_bytesink(upb_stdio *stdio);