inputstream.h

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/*
 * 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_
 
#ifdef __cplusplus
extern "C"
{
#endif
 
#include <stdbool.h>
#ifndef NDEBUG
#include <stdio.h>
#endif
#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>
 
typedef parserutils_error (*parserutils_charset_detect_func)(
        const uint8_t *data, size_t len, 
        uint16_t *mibenum, uint32_t *source);
 
typedef struct parserutils_inputstream 
{
    parserutils_buffer *utf8;   
    uint32_t cursor;        
    bool had_eof;           
} parserutils_inputstream;
 
/* Create an input stream */
parserutils_error parserutils_inputstream_create(const char *enc,
        uint32_t encsrc, parserutils_charset_detect_func csdetect,
        parserutils_inputstream **stream);
/* Destroy an input stream */
parserutils_error 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. */
parserutils_error parserutils_inputstream_peek_slow(
        parserutils_inputstream *stream, 
        size_t offset, const uint8_t **ptr, size_t *length);
 
static inline parserutils_error parserutils_inputstream_peek(
        parserutils_inputstream *stream, size_t offset, 
        const uint8_t **ptr, size_t *length)
{
    parserutils_error error = PARSERUTILS_OK;
    const parserutils_buffer *utf8;
    const uint8_t *utf8_data;
    size_t len, off, utf8_len;
 
    if (stream == NULL || ptr == NULL || length == NULL)
        return PARSERUTILS_BADPARM;
 
#ifndef NDEBUG
#ifdef VERBOSE_INPUTSTREAM
    fprintf(stdout, "Peek: len: %zu cur: %u off: %zu\n",
            stream->utf8->length, stream->cursor, offset);
#endif
#ifdef RANDOMISE_INPUTSTREAM
    parserutils_buffer_randomise(stream->utf8);
#endif
#endif
 
    utf8 = stream->utf8;
    utf8_data = utf8->data;
    utf8_len = utf8->length;
    off = stream->cursor + offset;
 
#define IS_ASCII(x) (((x) & 0x80) == 0)
 
    if (off < utf8_len) {
        if (IS_ASCII(utf8_data[off])) {
            /* Early exit for ASCII case */
            (*length) = 1;
            (*ptr) = (utf8_data + off);
            return PARSERUTILS_OK;
        } else {
            error = parserutils_charset_utf8_char_byte_length(
                utf8_data + off, &len);
 
            if (error == PARSERUTILS_OK) {
                (*length) = len;
                (*ptr) = (utf8_data + off);
                return PARSERUTILS_OK;
            } else if (error != PARSERUTILS_NEEDDATA) {
                return error;
            }
        }
    }
 
#undef IS_ASCII
 
    return parserutils_inputstream_peek_slow(stream, offset, ptr, length);
}
 
static inline void parserutils_inputstream_advance(
        parserutils_inputstream *stream, size_t bytes)
{
    if (stream == NULL)
        return;
 
#if !defined(NDEBUG) && defined(VERBOSE_INPUTSTREAM)
    fprintf(stdout, "Advance: len: %zu cur: %u bytes: %zu\n",
            stream->utf8->length, stream->cursor, bytes);
#endif
 
    if (bytes > stream->utf8->length - stream->cursor)
        bytes = stream->utf8->length - stream->cursor;
 
    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);
/* Change the document charset */
parserutils_error parserutils_inputstream_change_charset(
        parserutils_inputstream *stream, 
        const char *enc, uint32_t source);
 
#ifdef __cplusplus
}
#endif
 
#endif