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/*
* Copyright (C) 2012-2017 Robin Haberkorn
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <glib.h>
#include "sciteco.h"
#include "error.h"
#include "eol.h"
namespace SciTECO {
/**
* Read data with automatic EOL translation.
*
* This gets the next data block from the converter
* implementation, performs EOL translation (if enabled)
* in a more or less efficient manner and returns
* a chunk of EOL-normalized data.
*
* Since the underlying data source may have to be
* queried repeatedly and because EOLReader avoids
* reassembling the EOL-normalized data by returning
* references into the modified data source, it is
* necessary to call this function repeatedly until
* it returns NULL.
*
* Errors reading the data source are propagated
* (as exceptions).
*
* @param data_len The length of the data chunk returned
* by this function. Set on return.
* @return A pointer to a chunk of EOL-normalized
* data of length data_len.
* It is NOT null-terminated.
* NULL is returned when all data has been converted.
*/
const gchar *
EOLReader::convert(gsize &data_len)
{
if (last_char < 0) {
/* a CRLF was last translated */
block_len++;
last_char = '\n';
}
offset += block_len;
if (offset == read_len) {
offset = 0;
/*
* NOTE: This throws in case of errors
*/
if (!this->read(buffer, read_len)) {
/* EOF */
if (last_char == '\r') {
/*
* Very last character read is CR.
* If this is the only EOL so far, the
* EOL style is MAC.
* This is also executed if auto-eol is disabled
* but it doesn't hurt.
*/
if (eol_style < 0)
eol_style = SC_EOL_CR;
else if (eol_style != SC_EOL_CR)
eol_style_inconsistent = TRUE;
}
return NULL;
}
if (!(Flags::ed & Flags::ED_AUTOEOL)) {
/*
* No EOL translation - always return entire
* buffer
*/
data_len = block_len = read_len;
return buffer;
}
}
/*
* Return data with automatic EOL translation.
* Every EOL sequence is normalized to LF and
* the first sequence determines the documents
* EOL style.
* This loop is executed for every byte of the
* file/stream, so it was important to optimize
* it. Specifically, the number of returns
* is minimized by keeping a pointer to
* the beginning of a block of data in the buffer
* which already has LFs (offset).
* Mac EOLs can be converted to UNIX EOLs directly
* in the buffer.
* So if their EOLs are consistent, the function
* will return one block for the entire buffer.
* When reading a file with DOS EOLs, there will
* be one call per line which is significantly slower.
*/
for (guint i = offset; i < read_len; i++) {
switch (buffer[i]) {
case '\n':
if (last_char == '\r') {
if (eol_style < 0)
eol_style = SC_EOL_CRLF;
else if (eol_style != SC_EOL_CRLF)
eol_style_inconsistent = TRUE;
/*
* Return block. CR has already
* been made LF in `buffer`.
*/
data_len = block_len = i-offset;
/* next call will skip the CR */
last_char = -1;
return buffer + offset;
}
if (eol_style < 0)
eol_style = SC_EOL_LF;
else if (eol_style != SC_EOL_LF)
eol_style_inconsistent = TRUE;
/*
* No conversion necessary and no need to
* return block yet.
*/
last_char = '\n';
break;
case '\r':
if (last_char == '\r') {
if (eol_style < 0)
eol_style = SC_EOL_CR;
else if (eol_style != SC_EOL_CR)
eol_style_inconsistent = TRUE;
}
/*
* Convert CR to LF in `buffer`.
* This way more than one line using
* Mac EOLs can be returned at once.
*/
buffer[i] = '\n';
last_char = '\r';
break;
default:
if (last_char == '\r') {
if (eol_style < 0)
eol_style = SC_EOL_CR;
else if (eol_style != SC_EOL_CR)
eol_style_inconsistent = TRUE;
}
last_char = buffer[i];
break;
}
}
/*
* Return remaining block.
* With UNIX/MAC EOLs, this will usually be the
* entire `buffer`
*/
data_len = block_len = read_len-offset;
return buffer + offset;
}
bool
EOLReaderGIO::read(gchar *buffer, gsize &read_len)
{
GError *error = NULL;
switch (g_io_channel_read_chars(channel, buffer,
sizeof(EOLReaderGIO::buffer),
&read_len, &error)) {
case G_IO_STATUS_ERROR:
throw GlibError(error);
case G_IO_STATUS_EOF:
return false;
case G_IO_STATUS_NORMAL:
case G_IO_STATUS_AGAIN:
break;
}
return true;
}
bool
EOLReaderMem::read(gchar *buffer, gsize &read_len)
{
read_len = buffer_len;
buffer_len = 0;
/*
* On the first call, returns true,
* later false (no more data).
*/
return read_len != 0;
}
/*
* This could be in EOLReader as well, but this way, we
* make use of the buffer_len to avoid unnecessary allocations.
*/
gchar *
EOLReaderMem::convert_all(gsize *out_len)
{
GString *str = g_string_sized_new(buffer_len);
const gchar *data;
gsize data_len;
try {
while ((data = convert(data_len)))
g_string_append_len(str, data, data_len);
} catch (...) {
g_string_free(str, TRUE);
throw; /* forward */
}
if (out_len)
*out_len = str->len;
return g_string_free(str, FALSE);
}
/**
* Perform EOL-normalization on a buffer (if enabled) and
* pass it to the underlying data sink.
*
* This can be called repeatedly to transform a larger
* document - the buffer provided does not have to be
* well-formed with regard to EOL sequences.
*
* @param buffer The buffer to convert.
* @parem buffer_len The length of the data in buffer.
* @return The number of bytes written to the data sink,
* i.e. the size of the EOL-normalized data written.
*/
gsize
EOLWriter::convert(const gchar *buffer, gsize buffer_len)
{
gsize bytes_written;
guint i = 0;
guint block_start;
gsize block_written;
if (!(Flags::ed & Flags::ED_AUTOEOL))
/*
* Write without EOL-translation:
* `state` is not required
* NOTE: This throws in case of errors
*/
return this->write(buffer, buffer_len);
/*
* Write to stream with EOL-translation.
* The document's EOL mode tells us what was guessed
* when its content was read in (presumably from a file)
* but might have been changed manually by the user.
* NOTE: This code assumes that the output stream is
* buffered, since otherwise it would be slower
* (has been benchmarked).
* NOTE: The loop is executed for every character
* in `buffer` and has been optimized for minimal
* function (i.e. GIOChannel) calls.
*/
bytes_written = 0;
if (state == STATE_WRITE_LF) {
/* complete writing a CRLF sequence */
if (this->write("\n", 1) < 1)
return 0;
state = STATE_START;
bytes_written++;
i++;
}
block_start = i;
while (i < buffer_len) {
switch (buffer[i]) {
case '\n':
if (last_c == '\r') {
/* EOL sequence already written */
bytes_written++;
block_start = i+1;
break;
}
/* fall through */
case '\r':
block_written = this->write(buffer+block_start, i-block_start);
bytes_written += block_written;
if (block_written < i-block_start)
return bytes_written;
block_written = this->write(eol_seq, eol_seq_len);
if (block_written == 0)
return bytes_written;
if (block_written < eol_seq_len) {
/* incomplete EOL seq - we have written CR of CRLF */
state = STATE_WRITE_LF;
return bytes_written;
}
bytes_written++;
block_start = i+1;
break;
}
last_c = buffer[i++];
}
/*
* Write out remaining block (i.e. line)
*/
bytes_written += this->write(buffer+block_start, buffer_len-block_start);
return bytes_written;
}
gsize
EOLWriterGIO::write(const gchar *buffer, gsize buffer_len)
{
gsize bytes_written;
GError *error = NULL;
switch (g_io_channel_write_chars(channel, buffer, buffer_len,
&bytes_written, &error)) {
case G_IO_STATUS_ERROR:
throw GlibError(error);
case G_IO_STATUS_EOF:
case G_IO_STATUS_NORMAL:
case G_IO_STATUS_AGAIN:
break;
}
return bytes_written;
}
gsize
EOLWriterMem::write(const gchar *buffer, gsize buffer_len)
{
g_string_append_len(str, buffer, buffer_len);
return buffer_len;
}
} /* namespace SciTECO */
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