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/*************************************************************************
** FontCache.cpp **
** **
** This file is part of dvisvgm -- a fast DVI to SVG converter **
** Copyright (C) 2005-2017 Martin Gieseking <martin.gieseking@uos.de> **
** **
** 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/>. **
*************************************************************************/
#include <config.h>
#include <algorithm>
#include <cstring>
#include <fstream>
#include <iomanip>
#include <sstream>
#include "CRC32.hpp"
#include "FileSystem.hpp"
#include "FontCache.hpp"
#include "Glyph.hpp"
#include "Pair.hpp"
#include "StreamReader.hpp"
#include "StreamWriter.hpp"
using namespace std;
const uint8_t FontCache::FORMAT_VERSION = 5;
static Pair32 read_pair (int bytes, StreamReader &sr) {
int32_t x = sr.readSigned(bytes);
int32_t y = sr.readSigned(bytes);
return Pair32(x, y);
}
/** Removes all data from the cache. This does not affect the cache files. */
void FontCache::clear () {
_glyphs.clear();
_fontname.clear();
}
/** Assigns glyph data to a character and adds it to the cache.
* @param[in] c character code
* @param[in] glyph font glyph data */
void FontCache::setGlyph (int c, const Glyph &glyph) {
_glyphs[c] = glyph;
_changed = true;
}
/** Returns the corresponding glyph data of a given character of the current font.
* @param[in] c character code
* @return font glyph data (0 if no matching data was found) */
const Glyph* FontCache::getGlyph (int c) const {
GlyphMap::const_iterator it = _glyphs.find(c);
return (it != _glyphs.end()) ? &it->second : 0;
}
/** Writes the current cache data to a file (only if anything changed after
* the last call of read()).
* @param[in] fontname name of current font
* @param[in] dir directory where the cache file should go
* @return true if writing was successful */
bool FontCache::write (const char *fontname, const char *dir) const {
if (!_changed)
return true;
if (fontname && strlen(fontname) > 0) {
string dirstr = (dir == 0 || strlen(dir) == 0) ? FileSystem::getcwd() : dir;
ostringstream oss;
oss << dirstr << '/' << fontname << ".fgd";
ofstream ofs(oss.str().c_str(), ios::binary);
return write(fontname, ofs);
}
return false;
}
bool FontCache::write (const char* dir) const {
return _fontname.empty() ? false : write(_fontname.c_str(), dir);
}
/** Returns the minimal number of bytes needed to store the given value. */
static int max_int_size (int32_t value) {
int32_t limit = 0x7f;
for (int i=1; i <= 4; i++) {
if ((value < 0 && -value <= limit+1) || (value >= 0 && value <= limit))
return i;
limit = (limit << 8) | 0xff;
}
return 4;
}
/** Returns the minimal number of bytes needed to store the biggest
* pair component of the given vector. */
static int max_int_size (const Pair<int32_t> *pairs, size_t n) {
int ret=0;
for (size_t i=0; i < n; i++) {
ret = max(ret, max_int_size(pairs[i].x()));
ret = max(ret, max_int_size(pairs[i].y()));
}
return ret;
}
/** Writes the current cache data to a stream (only if anything changed after
* the last call of read()).
* @param[in] fontname name of current font
* @param[in] os output stream
* @return true if writing was successful */
bool FontCache::write (const char *fontname, ostream &os) const {
if (!_changed)
return true;
if (!os)
return false;
StreamWriter sw(os);
CRC32 crc32;
struct WriteActions : Glyph::Actions {
WriteActions (StreamWriter &sw, CRC32 &crc32) : _sw(sw), _crc32(crc32) {}
void draw (char cmd, const Glyph::Point *points, int n) override {
int bytes = max_int_size(points, n);
int cmdchar = (bytes << 5) | (cmd - 'A');
_sw.writeUnsigned(cmdchar, 1, _crc32);
for (int i=0; i < n; i++) {
_sw.writeSigned(points[i].x(), bytes, _crc32);
_sw.writeSigned(points[i].y(), bytes, _crc32);
}
}
StreamWriter &_sw;
CRC32 &_crc32;
} actions(sw, crc32);
sw.writeUnsigned(FORMAT_VERSION, 1, crc32);
sw.writeUnsigned(0, 4); // space for checksum
sw.writeString(fontname, crc32, true);
sw.writeUnsigned(_glyphs.size(), 4, crc32);
for (const auto &charglyphpair : _glyphs) {
const Glyph &glyph = charglyphpair.second;
sw.writeUnsigned(charglyphpair.first, 4, crc32);
sw.writeUnsigned(glyph.size(), 2, crc32);
glyph.iterate(actions, false);
}
os.seekp(1);
sw.writeUnsigned(crc32.get(), 4); // insert CRC32 checksum
os.seekp(0, ios::end);
return true;
}
/** Reads font glyph information from a file.
* @param[in] fontname name of font data to read
* @param[in] dir directory where the cache files are located
* @return true if reading was successful */
bool FontCache::read (const char *fontname, const char *dir) {
if (!fontname || strlen(fontname) == 0)
return false;
if (_fontname == fontname)
return true;
clear();
string dirstr = (dir == 0 || strlen(dir) == 0) ? FileSystem::getcwd() : dir;
ostringstream oss;
oss << dirstr << '/' << fontname << ".fgd";
ifstream ifs(oss.str().c_str(), ios::binary);
return read(fontname, ifs);
}
/** Reads font glyph information from a stream.
* @param[in] fontname name of font data to read
* @param[in] is input stream to read the glyph data from
* @return true if reading was successful */
bool FontCache::read (const char *fontname, istream &is) {
if (_fontname == fontname)
return true;
clear();
_fontname = fontname;
if (!is)
return false;
StreamReader sr(is);
CRC32 crc32;
if (sr.readUnsigned(1, crc32) != FORMAT_VERSION)
return false;
uint32_t crc32_cmp = sr.readUnsigned(4);
crc32.update(is);
if (crc32.get() != crc32_cmp)
return false;
is.clear();
is.seekg(5); // continue reading after checksum
string fname = sr.readString();
if (fname != fontname)
return false;
uint32_t num_glyphs = sr.readUnsigned(4);
while (num_glyphs-- > 0) {
uint32_t c = sr.readUnsigned(4); // character code
uint16_t s = sr.readUnsigned(2); // number of path commands
Glyph &glyph = _glyphs[c];
while (s-- > 0) {
uint8_t cmdval = sr.readUnsigned(1);
uint8_t cmdchar = (cmdval & 0x1f) + 'A';
int bytes = cmdval >> 5;
switch (cmdchar) {
case 'C': {
Pair32 p1 = read_pair(bytes, sr);
Pair32 p2 = read_pair(bytes, sr);
Pair32 p3 = read_pair(bytes, sr);
glyph.cubicto(p1, p2, p3);
break;
}
case 'L':
glyph.lineto(read_pair(bytes, sr));
break;
case 'M':
glyph.moveto(read_pair(bytes, sr));
break;
case 'Q': {
Pair32 p1 = read_pair(bytes, sr);
Pair32 p2 = read_pair(bytes, sr);
glyph.conicto(p1, p2);
break;
}
case 'Z':
glyph.closepath();
}
}
}
_changed = false;
return true;
}
/** Collects font cache information.
* @param[in] dirname path to font cache directory
* @param[out] infos the collected font information
* @param[out] invalid names of outdated/corrupted cache files
* @return true on success */
bool FontCache::fontinfo (const char *dirname, vector<FontInfo> &infos, vector<string> &invalid) {
infos.clear();
invalid.clear();
if (dirname) {
vector<string> fnames;
FileSystem::collect(dirname, fnames);
for (const string &fname : fnames) {
if (fname[0] == 'f' && fname.length() > 5 && fname.substr(fname.length()-4) == ".fgd") {
FontInfo info;
string path = string(dirname)+"/"+(fname.substr(1));
ifstream ifs(path.c_str(), ios::binary);
if (fontinfo(ifs, info))
infos.emplace_back(move(info));
else
invalid.emplace_back(fname.substr(1));
}
}
}
return !infos.empty();
}
/** Collects font cache information of a single font.
* @param[in] is input stream of the cache file
* @param[out] info the collected data
* @return true if data could be read, false if cache file is unavailable, outdated, or corrupted */
bool FontCache::fontinfo (std::istream &is, FontInfo &info) {
info.name.clear();
info.numchars = info.numbytes = info.numcmds = 0;
if (is) {
is.clear();
is.seekg(0);
try {
StreamReader sr(is);
CRC32 crc32;
if ((info.version = sr.readUnsigned(1, crc32)) != FORMAT_VERSION)
return false;
info.checksum = sr.readUnsigned(4);
crc32.update(is);
if (crc32.get() != info.checksum)
return false;
is.clear();
is.seekg(5); // continue reading after checksum
info.name = sr.readString();
info.numchars = sr.readUnsigned(4);
for (uint32_t i=0; i < info.numchars; i++) {
sr.readUnsigned(4); // character code
uint16_t s = sr.readUnsigned(2); // number of path commands
while (s-- > 0) {
uint8_t cmdval = sr.readUnsigned(1);
uint8_t cmdchar = (cmdval & 0x1f) + 'A';
int bytes = cmdval >> 5;
int bc = 0;
switch (cmdchar) {
case 'C': bc = 6*bytes; break;
case 'H':
case 'L':
case 'M':
case 'T':
case 'V': bc = 2*bytes; break;
case 'Q':
case 'S': bc = 4*bytes; break;
case 'Z': break;
default : return false;
}
info.numbytes += bc+1; // command length + command
info.numcmds++;
is.seekg(bc, ios::cur);
}
info.numbytes += 6; // number of path commands + char code
}
info.numbytes += 6+info.name.length(); // version + 0-byte + fontname + number of chars
}
catch (StreamReaderException &e) {
return false;
}
}
return true;
}
/** Collects font cache information and write it to a stream.
* @param[in] dirname path to font cache directory
* @param[in] os output is written to this stream
* @param[in] purge if true, outdated and corrupted cache files are removed */
void FontCache::fontinfo (const char *dirname, ostream &os, bool purge) {
if (dirname) {
ios::fmtflags osflags(os.flags());
vector<FontInfo> infos;
vector<string> invalid_files;
if (!fontinfo(dirname, infos, invalid_files))
os << "cache is empty\n";
else {
os << "cache format version " << infos[0].version << endl;
map<string, const FontInfo*> sortmap;
for (const FontInfo &info : infos)
sortmap[info.name] = &info;
for (const auto &strinfopair : sortmap) {
os << dec << setfill(' ') << left
<< setw(10) << left << strinfopair.second->name
<< setw(5) << right << strinfopair.second->numchars << " glyph" << (strinfopair.second->numchars == 1 ? ' ':'s')
<< setw(10) << right << strinfopair.second->numcmds << " cmd" << (strinfopair.second->numcmds == 1 ? ' ':'s')
<< setw(12) << right << strinfopair.second->numbytes << " byte" << (strinfopair.second->numbytes == 1 ? ' ':'s')
<< setw(6) << "crc:" << setw(8) << hex << right << setfill('0') << strinfopair.second->checksum
<< endl;
}
}
if (purge) {
for (const string &str : invalid_files) {
string path=string(dirname)+"/"+str;
if (FileSystem::remove(path))
os << "invalid cache file " << str << " removed\n";
}
}
os.flags(osflags); // restore format flags
}
}
|