From 57ad204ceaef0943bba11bdc5d4d98f2d179a22f Mon Sep 17 00:00:00 2001
From: Joshua Haberman <joshua@reverberate.org>
Date: Mon, 12 Jul 2010 01:04:14 -0700
Subject: Implemented upb_stdio (upb_bytesrc/upb_bytesink).

---
 stream/upb_stdio.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 stream/upb_stdio.h | 42 +++++++++++++++++++++++++++++++++++++
 2 files changed, 103 insertions(+)
 create mode 100644 stream/upb_stdio.c
 create mode 100644 stream/upb_stdio.h

diff --git a/stream/upb_stdio.c b/stream/upb_stdio.c
new file mode 100644
index 0000000..7cbca91
--- /dev/null
+++ b/stream/upb_stdio.c
@@ -0,0 +1,61 @@
+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * Copyright (c) 2010 Joshua Haberman.  See LICENSE for details.
+ */
+
+#include "upb_stdio.h"
+
+// We can make this configurable if necessary.
+#define BLOCK_SIZE 4096
+
+struct upb_stdio {
+  upb_bytesrc bytesrc;
+  upb_bytesink bytesink;
+  FILE *file;
+}
+
+static bool upb_stdio_read(upb_stdio *stdio, upb_string *str,
+                           int offset, int bytes_to_read) {
+  char *buf = upb_string_getrwbuf(offset + bytes_to_read) + offset;
+  size_t read = fread(buf, 1, bytes_to_read, stdio->file);
+  if(read < bytes_to_read) {
+    // Error or EOF.
+    stdio->bytesrc.eof = feof(stdio->file);
+    if(ferror(stdio->file)) {
+      upb_seterr(&stdio->bytesrc.status, UPB_STATUS_ERROR,
+                 "Error reading from stdio stream.");
+      return false;
+    }
+    // Resize to actual read size.
+    upb_string_getrwbuf(str, offset + read);
+  }
+  return true;
+}
+
+bool upb_stdio_get(upb_bytesrc *src, upb_string *str, upb_strlen_t minlen) {
+  // We ignore "minlen" since the stdio interfaces always return a full read
+  // unless they are at EOF.
+  (void)minlen;
+  return upb_stdio_read((upb_stdio*)src, str, 0, BLOCK_SIZE);
+}
+
+bool upb_stdio_append(upb_bytesrc *src, upb_string *str, upb_strlen_t len) {
+  return upb_stdio_read((upb_stdio*)src, str, upb_string_len(str), len);
+}
+
+int32_t upb_bytesink_put(upb_bytesink *sink, upb_string *str) {
+  upb_stdio *stdio = (upb_stdio*)sink - offsetof(upb_stdio, bytesink);
+  upb_strlen_t len = upb_string_len(str);
+  size_t written = fwrite(upb_string_getrobuf(str), 1, len, stdio->file);
+  if(written < len) {
+    // Error or EOF.
+    stdio->bytesink.eof = feof(stdio->file);
+    if(ferror(stdio->file)) {
+      upb_seterr(&stdio->bytesink.status, UPB_STATUS_ERROR,
+                 "Error writing to stdio stream.");
+      return 0;
+    }
+  }
+  return written;
+}
diff --git a/stream/upb_stdio.h b/stream/upb_stdio.h
new file mode 100644
index 0000000..3c29fcb
--- /dev/null
+++ b/stream/upb_stdio.h
@@ -0,0 +1,42 @@
+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * This file provides upb_bytesrc and upb_bytesink implementations for
+ * ANSI C stdio.
+ *
+ * Copyright (c) 2010 Joshua Haberman.  See LICENSE for details.
+ */
+
+#include <stdio.h>
+#include "upb_stream.h"
+
+#ifndef UPB_STDIO_H_
+#define UPB_STDIO_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct upb_stdio;
+typedef struct upb_stdio upb_stdio;
+
+// Creation/deletion.
+upb_stdio_ *upb_stdio__new();
+void upb_stdio_free(upb_stdio *stdio);
+
+// 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);
+
+// 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);
+
+#ifdef __cplusplus
+}  /* extern "C" */
+#endif
+
+#endif
-- 
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