Add pbstream_lowlevel.h.

pbstream_lowlevel.h

@@ -0,0 +1,49 @@
+/*
+ * pbstream - a stream-oriented implementation of protocol buffers.
+ *
+ * Copyright (c) 2008 Joshua Haberman.  See LICENSE for details.
+ *
+ * The structures and functions in this file offer more control than what is
+ * offered in pbstream.h.  These can be used for more specialized/optimized
+ * parsing applications. */
+
+#ifndef PBSTREAM_LOWLEVEL_H_
+#define PBSTREAM_LOWLEVEL_H_
+
+#include "pbstream.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* A tag occurs before each value on-the-wire. */
+struct pbstream_tag {
+  pbstream_field_number_t field_number;
+  pbstream_wire_type_t wire_type;
+};
+
+/* Parses a single tag from the character data starting at buf, and updates
+ * buf to point one past the bytes that were consumed. */
+pbstream_status_t parse_tag(char **buf, struct pbstream_tag *tag);
+
+/* Parses a wire value with the given type (which must have been obtained from
+ * a tag that was just parsed) and updates buf to point to one past the bytes
+ * that were consumed. */
+pbstream_status_t parse_wire_value(char **buf, size_t offset,
+                                   pbstream_wire_type_t wt,
+                                   union pbstream_wire_value *wv);
+
+/* Like the above, but discards the wire value instead of saving it. */
+pbstream_status_t skip_wire_value(char **buf, pbstream_wire_type_t wt);
+
+/* Looks the given field number up in the fieldset, and returns the
+ * corresponding pbstream_field definition (or NULL if this field number
+ * does not exist in this fieldset). */
+struct pbstream_field *pbstream_find_field(struct pbstream_fieldset *fs,
+                                           pbstream_field_number_t num);
+
+#ifdef __cplusplus
+}  /* extern "C" */
+#endif
+
+#endif  /* PBSTREAM_LOWLEVEL_H_ */