mirror of
https://github.com/moses-smt/mosesdecoder.git
synced 2024-09-11 11:25:40 +03:00
162 lines
6.8 KiB
C++
162 lines
6.8 KiB
C++
#include "lm/read_arpa.hh"
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#include "lm/blank.hh"
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#include "util/file.hh"
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#include <cmath>
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#include <cstdlib>
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#include <iostream>
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#include <sstream>
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#include <vector>
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#include <ctype.h>
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#include <string.h>
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#include <stdint.h>
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#ifdef WIN32
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#include <float.h>
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#endif
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namespace lm {
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// 1 for '\t', '\n', and ' '. This is stricter than isspace.
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const bool kARPASpaces[256] = {0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
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namespace {
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bool IsEntirelyWhiteSpace(const StringPiece &line) {
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for (size_t i = 0; i < static_cast<size_t>(line.size()); ++i) {
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if (!isspace(line.data()[i])) return false;
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}
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return true;
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}
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const char kBinaryMagic[] = "mmap lm http://kheafield.com/code";
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// strtoull isn't portable enough :-(
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uint64_t ReadCount(const std::string &from) {
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std::stringstream stream(from);
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uint64_t ret;
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stream >> ret;
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UTIL_THROW_IF(!stream, FormatLoadException, "Bad count " << from);
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return ret;
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}
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} // namespace
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void ReadARPACounts(util::FilePiece &in, std::vector<uint64_t> &number) {
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number.clear();
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StringPiece line = in.ReadLine();
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// In general, ARPA files can have arbitrary text before "\data\"
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// But in KenLM, we require such lines to start with "#", so that
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// we can do stricter error checking
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while (IsEntirelyWhiteSpace(line) || starts_with(line, "#")) {
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line = in.ReadLine();
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}
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if (line != "\\data\\") {
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if ((line.size() >= 2) && (line.data()[0] == 0x1f) && (static_cast<unsigned char>(line.data()[1]) == 0x8b)) {
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UTIL_THROW(FormatLoadException, "Looks like a gzip file. If this is an ARPA file, pipe " << in.FileName() << " through zcat. If this already in binary format, you need to decompress it because mmap doesn't work on top of gzip.");
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}
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if (static_cast<size_t>(line.size()) >= strlen(kBinaryMagic) && StringPiece(line.data(), strlen(kBinaryMagic)) == kBinaryMagic)
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UTIL_THROW(FormatLoadException, "This looks like a binary file but got sent to the ARPA parser. Did you compress the binary file or pass a binary file where only ARPA files are accepted?");
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UTIL_THROW_IF(line.size() >= 4 && StringPiece(line.data(), 4) == "blmt", FormatLoadException, "This looks like an IRSTLM binary file. Did you forget to pass --text yes to compile-lm?");
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UTIL_THROW_IF(line == "iARPA", FormatLoadException, "This looks like an IRSTLM iARPA file. You need an ARPA file. Run\n compile-lm --text yes " << in.FileName() << " " << in.FileName() << ".arpa\nfirst.");
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UTIL_THROW(FormatLoadException, "first non-empty line was \"" << line << "\" not \\data\\.");
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}
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while (!IsEntirelyWhiteSpace(line = in.ReadLine())) {
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if (line.size() < 6 || strncmp(line.data(), "ngram ", 6)) UTIL_THROW(FormatLoadException, "count line \"" << line << "\"doesn't begin with \"ngram \"");
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// So strtol doesn't go off the end of line.
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std::string remaining(line.data() + 6, line.size() - 6);
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char *end_ptr;
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unsigned int length = std::strtol(remaining.c_str(), &end_ptr, 10);
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if ((end_ptr == remaining.c_str()) || (length - 1 != number.size())) UTIL_THROW(FormatLoadException, "ngram count lengths should be consecutive starting with 1: " << line);
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if (*end_ptr != '=') UTIL_THROW(FormatLoadException, "Expected = immediately following the first number in the count line " << line);
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++end_ptr;
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number.push_back(ReadCount(end_ptr));
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}
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}
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void ReadNGramHeader(util::FilePiece &in, unsigned int length) {
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StringPiece line;
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while (IsEntirelyWhiteSpace(line = in.ReadLine())) {}
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std::stringstream expected;
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expected << '\\' << length << "-grams:";
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if (line != expected.str()) UTIL_THROW(FormatLoadException, "Was expecting n-gram header " << expected.str() << " but got " << line << " instead");
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}
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void ReadBackoff(util::FilePiece &in, Prob &/*weights*/) {
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switch (in.get()) {
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case '\t':
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{
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float got = in.ReadFloat();
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if (got != 0.0)
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UTIL_THROW(FormatLoadException, "Non-zero backoff " << got << " provided for an n-gram that should have no backoff");
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}
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break;
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case '\n':
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break;
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default:
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UTIL_THROW(FormatLoadException, "Expected tab or newline for backoff");
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}
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}
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void ReadBackoff(util::FilePiece &in, float &backoff) {
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// Always make zero negative.
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// Negative zero means that no (n+1)-gram has this n-gram as context.
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// Therefore the hypothesis state can be shorter. Of course, many n-grams
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// are context for (n+1)-grams. An algorithm in the data structure will go
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// back and set the backoff to positive zero in these cases.
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switch (in.get()) {
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case '\t':
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backoff = in.ReadFloat();
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if (backoff == ngram::kExtensionBackoff) backoff = ngram::kNoExtensionBackoff;
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{
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#ifdef WIN32
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int float_class = _fpclass(backoff);
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UTIL_THROW_IF(float_class == _FPCLASS_SNAN || float_class == _FPCLASS_QNAN || float_class == _FPCLASS_NINF || float_class == _FPCLASS_PINF, FormatLoadException, "Bad backoff " << backoff);
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#else
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int float_class = std::fpclassify(backoff);
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UTIL_THROW_IF(float_class == FP_NAN || float_class == FP_INFINITE, FormatLoadException, "Bad backoff " << backoff);
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#endif
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}
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UTIL_THROW_IF(in.get() != '\n', FormatLoadException, "Expected newline after backoff");
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break;
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case '\n':
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backoff = ngram::kNoExtensionBackoff;
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break;
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default:
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UTIL_THROW(FormatLoadException, "Expected tab or newline for backoff");
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}
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}
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void ReadEnd(util::FilePiece &in) {
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StringPiece line;
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do {
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line = in.ReadLine();
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} while (IsEntirelyWhiteSpace(line));
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if (line != "\\end\\") UTIL_THROW(FormatLoadException, "Expected \\end\\ but the ARPA file has " << line);
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try {
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while (true) {
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line = in.ReadLine();
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if (!IsEntirelyWhiteSpace(line)) UTIL_THROW(FormatLoadException, "Trailing line " << line);
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}
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} catch (const util::EndOfFileException &e) {}
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}
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void PositiveProbWarn::Warn(float prob) {
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switch (action_) {
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case THROW_UP:
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UTIL_THROW(FormatLoadException, "Positive log probability " << prob << " in the model. This is a bug in IRSTLM; you can set config.positive_log_probability = SILENT or pass -i to build_binary to substitute 0.0 for the log probability. Error");
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case COMPLAIN:
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std::cerr << "There's a positive log probability " << prob << " in the APRA file, probably because of a bug in IRSTLM. This and subsequent entires will be mapped to 0 log probability." << std::endl;
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action_ = SILENT;
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break;
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case SILENT:
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break;
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}
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}
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} // namespace lm
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