From 2777a04ed2ba4fd36138b991d66a32a283361f7e Mon Sep 17 00:00:00 2001
From: John Mark Bell <jmb@netsurf-browser.org>
Date: Thu, 1 May 2008 16:34:46 +0000
Subject: Import parser construction utility library

svn path=/trunk/libparserutils/; revision=4111
---
 include/parserutils/input/inputstream.h | 143 ++++++++++++++++++++++++++++++++
 1 file changed, 143 insertions(+)
 create mode 100644 include/parserutils/input/inputstream.h

(limited to 'include/parserutils/input/inputstream.h')

diff --git a/include/parserutils/input/inputstream.h b/include/parserutils/input/inputstream.h
new file mode 100644
index 0000000..2b0c407
--- /dev/null
+++ b/include/parserutils/input/inputstream.h
@@ -0,0 +1,143 @@
+/*
+ * This file is part of LibParserUtils.
+ * Licensed under the MIT License,
+ *                http://www.opensource.org/licenses/mit-license.php
+ * Copyright 2007 John-Mark Bell <jmb@netsurf-browser.org>
+ */
+
+#ifndef parserutils_input_inputstream_h_
+#define parserutils_input_inputstream_h_
+
+#include <stdbool.h>
+#include <stdlib.h>
+#include <inttypes.h>
+
+#include <parserutils/errors.h>
+#include <parserutils/functypes.h>
+#include <parserutils/types.h>
+#include <parserutils/charset/utf8.h>
+#include <parserutils/utils/buffer.h>
+
+/**
+ * Type of charset detection function
+ */
+typedef parserutils_error (*parserutils_charset_detect_func)(
+		const uint8_t *data, size_t len, 
+		uint16_t *mibenum, uint32_t *source);
+
+/**
+ * Input stream object
+ */
+typedef struct parserutils_inputstream 
+{
+	parserutils_buffer *utf8;	/**< Buffer containing utf8 data */
+
+	uint32_t cursor;		/**< Byte offset of current position */
+
+	bool had_eof;			/**< Whether EOF has been reached */
+} parserutils_inputstream;
+
+/* EOF pseudo-character */
+#define PARSERUTILS_INPUTSTREAM_EOF (0xFFFFFFFFU)
+/* Out-of-data indicator */
+#define PARSERUTILS_INPUTSTREAM_OOD (0xFFFFFFFEU)
+
+/* Create an input stream */
+parserutils_inputstream *parserutils_inputstream_create(const char *enc,
+		uint32_t encsrc, parserutils_charset_detect_func csdetect,
+		parserutils_alloc alloc, void *pw);
+/* Destroy an input stream */
+void parserutils_inputstream_destroy(parserutils_inputstream *stream);
+
+/* Append data to an input stream */
+parserutils_error parserutils_inputstream_append(
+		parserutils_inputstream *stream,
+		const uint8_t *data, size_t len);
+/* Insert data into stream at current location */
+parserutils_error parserutils_inputstream_insert(
+		parserutils_inputstream *stream,
+		const uint8_t *data, size_t len);
+
+/* Slow form of css_inputstream_peek. */
+uintptr_t parserutils_inputstream_peek_slow(parserutils_inputstream *stream, 
+		size_t offset, size_t *length);
+
+/* Look at the character in the stream that starts at 
+ * offset bytes from the cursor
+ *
+ * \param stream  Stream to look in
+ * \param offset  Byte offset of start of character
+ * \param length  Pointer to location to receive character length (in bytes)
+ * \return Pointer to character data, or EOF or OOD.
+ *
+ * Once the character pointed to by the result of this call has been advanced
+ * past (i.e. parserutils_inputstream_advance has caused the stream cursor to 
+ * pass over the character), then no guarantee is made as to the validity of 
+ * the data pointed to. Thus, any attempt to dereference the pointer after 
+ * advancing past the data it points to is a bug.
+ */
+static inline uintptr_t parserutils_inputstream_peek(
+		parserutils_inputstream *stream, size_t offset, size_t *length)
+{
+	parserutils_error error = PARSERUTILS_OK;
+	size_t len;
+
+	if (stream == NULL)
+		return PARSERUTILS_INPUTSTREAM_OOD;
+
+#define IS_ASCII(x) (((x) & 0x80) == 0)
+
+	if (stream->cursor + offset < stream->utf8->length) {
+		if (IS_ASCII(stream->utf8->data[stream->cursor + offset])) {
+			len = 1;
+		} else {
+			error = parserutils_charset_utf8_char_byte_length(
+				stream->utf8->data + stream->cursor + offset,
+				&len);
+
+			if (error != PARSERUTILS_OK && 
+					error != PARSERUTILS_NEEDDATA)
+				return PARSERUTILS_INPUTSTREAM_OOD;
+		}
+	}
+
+#undef IS_ASCII
+
+	if (stream->cursor + offset == stream->utf8->length ||
+			error == PARSERUTILS_NEEDDATA) {
+		return parserutils_inputstream_peek_slow(stream, 
+				offset, length);
+	}
+
+	*length = len;
+
+	return (uintptr_t) (stream->utf8->data + stream->cursor + offset);
+}
+
+/**
+ * Advance the stream's current position
+ *
+ * \param stream  The stream whose position to advance
+ * \param bytes   The number of bytes to advance
+ */
+static inline void parserutils_inputstream_advance(
+		parserutils_inputstream *stream, size_t bytes)
+{
+	if (stream == NULL)
+		return;
+
+	if (bytes > stream->utf8->length - stream->cursor)
+		abort();
+
+	if (stream->cursor == stream->utf8->length)
+		return;
+
+	stream->cursor += bytes;
+}
+
+/* Read the document charset */
+const char *parserutils_inputstream_read_charset(
+		parserutils_inputstream *stream, uint32_t *source);
+
+#endif
+
-- 
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