Sync to internal Google development.

1 files changed, 73 insertions, 0 deletions

diff --git a/upb/bindings/stdc/io.h b/upb/bindings/stdc/io.h
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+++ b/upb/bindings/stdc/io.h
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+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * Copyright (c) 2012 Google Inc.  See LICENSE for details.
+ * Author: Josh Haberman <jhaberman@gmail.com>
+ *
+ * ANSI C file I/O.
+ */
+
+#ifndef UPB_STDC_IO_H_
+#define UPB_STDC_IO_H_
+
+#include <stdio.h>
+#include "upb/bytestream.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* upb_stdio ******************************************************************/
+
+// bytesrc/bytesink for 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).
+
+typedef struct {
+  uint64_t ofs;
+  size_t len;
+  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;
+  int nbuf;
+  uint32_t 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);
+
+// 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);
+
+upb_bytesrc *upb_stdio_bytesrc(upb_stdio *stdio);
+upb_bytesink *upb_stdio_bytesink(upb_stdio *stdio);
+
+#ifdef __cplusplus
+}  /* extern "C" */
+#endif
+
+#endif  /* UPB_STDC_IO_H_ */