1 files changed, 384 insertions, 0 deletions
diff --git a/src/input/filter.c b/src/input/filter.c
new file mode 100644
index 0000000..f40c98f
--- /dev/null
+++ b/src/input/filter.c
@@ -0,0 +1,384 @@
+/*
+ * 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>
+ */
+
+#include <errno.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifdef WITH_ICONV_FILTER
+#include <iconv.h>
+#endif
+
+#include <parserutils/charset/mibenum.h>
+#include <parserutils/charset/codec.h>
+
+#include "input/filter.h"
+#include "utils/utils.h"
+
+/** Input filter */
+struct parserutils_filter {
+#ifdef WITH_ICONV_FILTER
+	iconv_t cd;			/**< Iconv conversion descriptor */
+	uint16_t int_enc;		/**< The internal encoding */
+#else
+	parserutils_charset_codec *read_codec;	/**< Read codec */
+	parserutils_charset_codec *write_codec;	/**< Write codec */
+
+	uint32_t pivot_buf[64];		/**< Conversion pivot buffer */
+
+	bool leftover;			/**< Data remains from last call */
+	uint8_t *pivot_left;		/**< Remaining pivot to write */
+	size_t pivot_len;		/**< Length of pivot remaining */
+#endif
+
+	struct {
+		uint16_t encoding;	/**< Input encoding */
+	} settings;			/**< Filter settings */
+
+	parserutils_alloc alloc;	/**< Memory (de)allocation function */
+	void *pw;			/**< Client private data */
+};
+
+static parserutils_error filter_set_defaults(parserutils_filter *input);
+static parserutils_error filter_set_encoding(parserutils_filter *input,
+		const char *enc);
+
+/**
+ * Create an input filter
+ *
+ * \param int_enc  Desired encoding of document
+ * \param alloc    Function used to (de)allocate data
+ * \param pw       Pointer to client-specific private data (may be NULL)
+ * \return Pointer to filter instance, or NULL on failure
+ */
+parserutils_filter *parserutils_filter_create(const char *int_enc,
+		parserutils_alloc alloc, void *pw)
+{
+	parserutils_filter *filter;
+
+	if (int_enc == NULL || alloc == NULL)
+		return NULL;
+
+	filter = alloc(NULL, sizeof(*filter), pw);
+	if (!filter)
+		return NULL;
+
+#ifdef WITH_ICONV_FILTER
+	filter->cd = (iconv_t) -1;
+	filter->int_enc = parserutils_charset_mibenum_from_name(
+			int_enc, strlen(int_enc));
+	if (filter->int_enc == 0) {
+		alloc(filter, 0, pw);
+		return NULL;
+	}
+#else
+	filter->leftover = false;
+	filter->pivot_left = NULL;
+	filter->pivot_len = 0;
+#endif
+
+	filter->alloc = alloc;
+	filter->pw = pw;
+
+	if (filter_set_defaults(filter) != PARSERUTILS_OK) {
+		filter->alloc(filter, 0, pw);
+		return NULL;
+	}
+
+#ifndef WITH_ICONV_FILTER
+	filter->write_codec = 
+			parserutils_charset_codec_create(int_enc, alloc, pw);
+	if (filter->write_codec == NULL) {
+		if (filter->read_codec != NULL)
+			parserutils_charset_codec_destroy(filter->read_codec);
+		filter->alloc(filter, 0, pw);
+		return NULL;
+	}
+#endif
+
+	return filter;
+}
+
+/**
+ * Destroy an input filter
+ *
+ * \param input  Pointer to filter instance
+ */
+void parserutils_filter_destroy(parserutils_filter *input)
+{
+	if (input == NULL)
+		return;
+
+#ifdef WITH_ICONV_FILTER
+	if (input->cd != (iconv_t) -1)
+		iconv_close(input->cd);
+#else
+	if (input->read_codec != NULL)
+		parserutils_charset_codec_destroy(input->read_codec);
+
+	if (input->write_codec != NULL)
+		parserutils_charset_codec_destroy(input->write_codec);
+#endif
+
+	input->alloc(input, 0, input->pw);
+
+	return;
+}
+
+/**
+ * Configure an input filter
+ *
+ * \param input   Pointer to filter instance
+ * \param type    Input option type to configure
+ * \param params  Option-specific parameters
+ * \return PARSERUTILS_OK on success, appropriate error otherwise
+ */
+parserutils_error parserutils_filter_setopt(parserutils_filter *input,
+		parserutils_filter_opttype type,
+		parserutils_filter_optparams *params)
+{
+	parserutils_error error = PARSERUTILS_OK;
+
+	if (input == NULL || params == NULL)
+		return PARSERUTILS_BADPARM;
+
+	switch (type) {
+	case PARSERUTILS_FILTER_SET_ENCODING:
+		error = filter_set_encoding(input, params->encoding.name);
+		break;
+	}
+
+	return error;
+}
+
+/**
+ * Process a chunk of data
+ *
+ * \param input   Pointer to filter instance
+ * \param data    Pointer to pointer to input buffer
+ * \param len     Pointer to length of input buffer
+ * \param output  Pointer to pointer to output buffer
+ * \param outlen  Pointer to length of output buffer
+ * \return PARSERUTILS_OK on success, appropriate error otherwise
+ *
+ * Call this with an input buffer length of 0 to flush any buffers.
+ */
+parserutils_error parserutils_filter_process_chunk(parserutils_filter *input,
+		const uint8_t **data, size_t *len,
+		uint8_t **output, size_t *outlen)
+{
+	if (input == NULL || data == NULL || *data == NULL || len == NULL ||
+			output == NULL || *output == NULL || outlen == NULL)
+		return PARSERUTILS_BADPARM;
+
+#ifdef WITH_ICONV_FILTER
+	if (iconv(input->cd, (char **) data, len, 
+			(char **) output, outlen) == (size_t) -1) {
+		switch (errno) {
+		case E2BIG:
+			return PARSERUTILS_NOMEM;
+		case EILSEQ:
+			if (*outlen < 3)
+				return PARSERUTILS_NOMEM;
+
+			(*output)[0] = 0xef;
+			(*output)[1] = 0xbf;
+			(*output)[2] = 0xbd;
+
+			*output += 3;
+			*outlen -= 3;
+
+			(*data)++;
+			(*len)--;
+
+			while (*len > 0) {
+				size_t ret;
+				
+				ret = iconv(input->cd, (char **) data, len, 
+						(char **) output, outlen);
+				if (ret != (size_t) -1 || errno != EILSEQ)
+					break;
+
+				(*data)++;
+				(*len)--;
+			}
+
+			return errno == E2BIG ? PARSERUTILS_NOMEM 
+					      : PARSERUTILS_OK;
+		}
+	}
+
+	return PARSERUTILS_OK;
+#else
+	parserutils_error read_error, write_error;
+
+	if (input->leftover) {
+		/* Some data left to be written from last call */
+
+		/* Attempt to flush the remaining data. */
+		write_error = parserutils_charset_codec_encode(
+				input->write_codec,
+				(const uint8_t **) &input->pivot_left,
+				&input->pivot_len,
+				output, outlen);
+
+		if (write_error != PARSERUTILS_OK)
+			return write_error;
+
+
+		/* And clear leftover */
+		input->pivot_left = NULL;
+		input->pivot_len = 0;
+		input->leftover = false;
+	}
+
+	while (*len > 0) {
+		size_t pivot_len = sizeof(input->pivot_buf);
+		uint8_t *pivot = (uint8_t *) input->pivot_buf;
+
+		read_error = parserutils_charset_codec_decode(input->read_codec,
+				data, len,
+				(uint8_t **) &pivot, &pivot_len);
+
+		pivot = (uint8_t *) input->pivot_buf;
+		pivot_len = sizeof(input->pivot_buf) - pivot_len;
+
+		if (pivot_len > 0) {
+			write_error = parserutils_charset_codec_encode(
+					input->write_codec,
+					(const uint8_t **) &pivot,
+					&pivot_len,
+					output, outlen);
+
+			if (write_error != PARSERUTILS_OK) {
+				input->leftover = true;
+				input->pivot_left = pivot;
+				input->pivot_len = pivot_len;
+
+				return write_error;
+			}
+		}
+
+		if (read_error != PARSERUTILS_OK && 
+				read_error != PARSERUTILS_NOMEM)
+			return read_error;
+	}
+
+	return PARSERUTILS_OK;
+#endif
+}
+
+/**
+ * Reset an input filter's state
+ *
+ * \param input  The input filter to reset
+ * \param PARSERUTILS_OK on success, appropriate error otherwise
+ */
+parserutils_error parserutils_filter_reset(parserutils_filter *input)
+{
+	if (input == NULL)
+		return PARSERUTILS_BADPARM;
+
+#ifdef WITH_ICONV_FILTER
+	iconv(input->cd, NULL, 0, NULL, 0);
+#else
+	parserutils_error error;
+
+	/* Clear pivot buffer leftovers */
+	input->pivot_left = NULL;
+	input->pivot_len = 0;
+	input->leftover = false;
+
+	/* Reset read codec */
+	error = parserutils_charset_codec_reset(input->read_codec);
+	if (error != PARSERUTILS_OK)
+		return error;
+
+	/* Reset write codec */
+	error = parserutils_charset_codec_reset(input->write_codec);
+	if (error != PARSERUTILS_OK)
+		return error;
+#endif
+
+	return PARSERUTILS_OK;
+}
+
+/**
+ * Set an input filter's default settings
+ *
+ * \param input  Input filter to configure
+ * \return PARSERUTILS_OK on success, appropriate error otherwise
+ */
+parserutils_error filter_set_defaults(parserutils_filter *input)
+{
+	parserutils_error error;
+
+	if (input == NULL)
+		return PARSERUTILS_BADPARM;
+
+#ifndef WITH_ICONV_FILTER
+	input->read_codec = NULL;
+	input->write_codec = NULL;
+#endif
+
+	input->settings.encoding = 0;
+	error = filter_set_encoding(input, "UTF-8");
+	if (error != PARSERUTILS_OK)
+		return error;
+
+	return PARSERUTILS_OK;
+}
+
+/**
+ * Set an input filter's encoding
+ *
+ * \param input  Input filter to configure
+ * \param enc    Encoding name
+ * \return PARSERUTILS_OK on success, appropriate error otherwise
+ */
+parserutils_error filter_set_encoding(parserutils_filter *input,
+		const char *enc)
+{
+	const char *old_enc;
+	uint16_t mibenum;
+
+	if (input == NULL || enc == NULL)
+		return PARSERUTILS_BADPARM;
+
+	mibenum = parserutils_charset_mibenum_from_name(enc, strlen(enc));
+	if (mibenum == 0)
+		return PARSERUTILS_INVALID;
+
+	/* Exit early if we're already using this encoding */
+	if (input->settings.encoding == mibenum)
+		return PARSERUTILS_OK;
+
+	old_enc = parserutils_charset_mibenum_to_name(input->settings.encoding);
+	if (old_enc == NULL)
+		old_enc = "UTF-8";
+
+#ifdef WITH_ICONV_FILTER
+	if (input->cd != (iconv_t) -1)
+		iconv_close(input->cd);
+
+	input->cd = iconv_open(
+		parserutils_charset_mibenum_to_name(input->int_enc), enc);
+#else
+	if (input->read_codec != NULL)
+		parserutils_charset_codec_destroy(input->read_codec);
+
+	input->read_codec = parserutils_charset_codec_create(enc, input->alloc,
+			input->pw);
+	if (input->read_codec == NULL)
+		return PARSERUTILS_NOMEM;
+#endif
+
+	input->settings.encoding = mibenum;
+
+	return PARSERUTILS_OK;
+}