X-Git-Url: https://git.sesse.net/?p=plocate;a=blobdiff_plain;f=database-builder.cpp;h=066b60eaeb56ecd6ccc556fb1a091d2faff40d8b;hp=89a06d6c59a52399a11c05a6513df780f4edb281;hb=HEAD;hpb=04182a570c30c5bac97cbe52a51f8e7a174b5451 diff --git a/database-builder.cpp b/database-builder.cpp index 89a06d6..f9dfb71 100644 --- a/database-builder.cpp +++ b/database-builder.cpp @@ -5,6 +5,9 @@ #include #include +#ifdef HAS_ENDIAN_H +#include +#endif #include #include #include @@ -26,29 +29,19 @@ constexpr unsigned num_overflow_slots = 16; string zstd_compress(const string &src, ZSTD_CDict *cdict, string *tempbuf); -static inline uint32_t read_unigram(const string_view s, size_t idx) -{ - if (idx < s.size()) { - return (unsigned char)s[idx]; - } else { - return 0; - } -} - -static inline uint32_t read_trigram(const string_view s, size_t start) -{ - return read_unigram(s, start) | - (read_unigram(s, start + 1) << 8) | - (read_unigram(s, start + 2) << 16); -} - class PostingListBuilder { public: inline void add_docid(uint32_t docid); + inline void add_first_docid(uint32_t docid); void finish(); - string encoded; - size_t num_docids = 0; + vector encoded; + size_t get_num_docids() const + { + // Updated only when we flush, so check that we're finished. + assert(pending_deltas.empty()); + return num_docids; + } private: void write_header(uint32_t docid); @@ -56,7 +49,8 @@ private: vector pending_deltas; - uint32_t last_block_end, last_docid = -1; + uint32_t num_docids = 0; // Should be size_t, except the format only supports 2^32 docids per posting list anyway. + uint32_t last_docid = -1; }; void PostingListBuilder::add_docid(uint32_t docid) @@ -66,22 +60,20 @@ void PostingListBuilder::add_docid(uint32_t docid) return; } - if (num_docids == 0) { - // Very first docid. - write_header(docid); - ++num_docids; - last_block_end = last_docid = docid; - return; - } - pending_deltas.push_back(docid - last_docid - 1); last_docid = docid; if (pending_deltas.size() == 128) { append_block(); pending_deltas.clear(); - last_block_end = docid; + num_docids += 128; } +} + +void PostingListBuilder::add_first_docid(uint32_t docid) +{ + write_header(docid); ++num_docids; + last_docid = docid; } void PostingListBuilder::finish() @@ -95,7 +87,10 @@ void PostingListBuilder::finish() // No interleaving for partial blocks. unsigned char buf[P4NENC_BOUND(128)]; unsigned char *end = encode_pfor_single_block<128>(pending_deltas.data(), pending_deltas.size(), /*interleaved=*/false, buf); - encoded.append(reinterpret_cast(buf), reinterpret_cast(end)); + encoded.insert(encoded.end(), buf, end); + + num_docids += pending_deltas.size(); + pending_deltas.clear(); } void PostingListBuilder::append_block() @@ -103,14 +98,14 @@ void PostingListBuilder::append_block() unsigned char buf[P4NENC_BOUND(128)]; assert(pending_deltas.size() == 128); unsigned char *end = encode_pfor_single_block<128>(pending_deltas.data(), 128, /*interleaved=*/true, buf); - encoded.append(reinterpret_cast(buf), reinterpret_cast(end)); + encoded.insert(encoded.end(), buf, end); } void PostingListBuilder::write_header(uint32_t docid) { unsigned char buf[P4NENC_BOUND(1)]; unsigned char *end = write_baseval(docid, buf); - encoded.append(reinterpret_cast(buf), end - buf); + encoded.insert(encoded.end(), buf, end); } void DictionaryBuilder::add_file(string filename, dir_time) @@ -175,8 +170,59 @@ string DictionaryBuilder::train(size_t buf_size) return buf; } -Corpus::Corpus(FILE *outfp, size_t block_size, ZSTD_CDict *cdict, bool store_dir_times) - : invindex(new PostingListBuilder *[NUM_TRIGRAMS]), outfp(outfp), block_size(block_size), store_dir_times(store_dir_times), cdict(cdict) +class EncodingCorpus : public DatabaseReceiver { +public: + EncodingCorpus(FILE *outfp, size_t block_size, ZSTD_CDict *cdict, bool store_dir_times); + ~EncodingCorpus(); + + void add_file(std::string filename, dir_time dt) override; + void flush_block() override; + void finish() override; + + std::vector filename_blocks; + size_t num_files = 0, num_files_in_block = 0, num_blocks = 0; + bool seen_trigram(uint32_t trgm) + { + return invindex[trgm] != nullptr; + } + size_t num_files_seen() const override { return num_files; } + PostingListBuilder &get_pl_builder(uint32_t trgm) + { + return *invindex[trgm]; + } + + void add_docid(uint32_t trgm, uint32_t docid) + { + if (invindex[trgm] == nullptr) { + invindex[trgm] = new PostingListBuilder; + invindex[trgm]->add_first_docid(docid); + } else { + invindex[trgm]->add_docid(docid); + } + } + + size_t num_trigrams() const; + std::string get_compressed_dir_times(); + +private: + void compress_dir_times(size_t allowed_slop); + + std::unique_ptr invindex; + FILE *outfp; + off_t outfp_pos; // Cheaper than calling ftell(outfp) all the time. + std::string current_block; + std::string tempbuf; + const size_t block_size; + const bool store_dir_times; + ZSTD_CDict *cdict; + + ZSTD_CStream *dir_time_ctx = nullptr; + std::string dir_times; // Buffer of still-uncompressed data. + std::string dir_times_compressed; +}; + +EncodingCorpus::EncodingCorpus(FILE *outfp, size_t block_size, ZSTD_CDict *cdict, bool store_dir_times) + : invindex(new PostingListBuilder *[NUM_TRIGRAMS]), outfp(outfp), outfp_pos(ftell(outfp)), block_size(block_size), store_dir_times(store_dir_times), cdict(cdict) { fill(invindex.get(), invindex.get() + NUM_TRIGRAMS, nullptr); if (store_dir_times) { @@ -185,22 +231,14 @@ Corpus::Corpus(FILE *outfp, size_t block_size, ZSTD_CDict *cdict, bool store_dir } } -Corpus::~Corpus() +EncodingCorpus::~EncodingCorpus() { for (unsigned i = 0; i < NUM_TRIGRAMS; ++i) { delete invindex[i]; } } -PostingListBuilder &Corpus::get_pl_builder(uint32_t trgm) -{ - if (invindex[trgm] == nullptr) { - invindex[trgm] = new PostingListBuilder; - } - return *invindex[trgm]; -} - -void Corpus::add_file(string filename, dir_time dt) +void EncodingCorpus::add_file(string filename, dir_time dt) { ++num_files; if (!current_block.empty()) { @@ -224,7 +262,7 @@ void Corpus::add_file(string filename, dir_time dt) } } -void Corpus::compress_dir_times(size_t allowed_slop) +void EncodingCorpus::compress_dir_times(size_t allowed_slop) { while (dir_times.size() >= allowed_slop) { size_t old_size = dir_times_compressed.size(); @@ -256,7 +294,7 @@ void Corpus::compress_dir_times(size_t allowed_slop) } } -void Corpus::flush_block() +void EncodingCorpus::flush_block() { if (current_block.empty()) { return; @@ -266,36 +304,58 @@ void Corpus::flush_block() // Create trigrams. const char *ptr = current_block.c_str(); - while (ptr < current_block.c_str() + current_block.size()) { - string_view s(ptr); - if (s.size() >= 3) { - for (size_t j = 0; j < s.size() - 2; ++j) { - uint32_t trgm = read_trigram(s, j); - get_pl_builder(trgm).add_docid(docid); + const char *end = ptr + current_block.size(); + while (ptr < end - 3) { // Must be at least one filename left, that's at least three bytes. + if (ptr[0] == '\0') { + // This filename is zero bytes, so skip it (and the zero terminator). + ++ptr; + continue; + } else if (ptr[1] == '\0') { + // This filename is one byte, so skip it (and the zero terminator). + ptr += 2; + continue; + } else if (ptr[2] == '\0') { + // This filename is two bytes, so skip it (and the zero terminator). + ptr += 3; + continue; + } + for (;;) { + // NOTE: Will read one byte past the end of the trigram, but it's OK, + // since we always call it from contexts where there's a terminating zero byte. + uint32_t trgm; + memcpy(&trgm, ptr, sizeof(trgm)); + ++ptr; + trgm = le32toh(trgm); + add_docid(trgm & 0xffffff, docid); + if (trgm <= 0xffffff) { + // Terminating zero byte, so we're done with this filename. + // Skip the remaining two bytes, and the zero terminator. + ptr += 3; + break; } } - ptr += s.size() + 1; } // Compress and add the filename block. - filename_blocks.push_back(ftell(outfp)); + filename_blocks.push_back(outfp_pos); string compressed = zstd_compress(current_block, cdict, &tempbuf); if (fwrite(compressed.data(), compressed.size(), 1, outfp) != 1) { perror("fwrite()"); exit(1); } + outfp_pos += compressed.size(); current_block.clear(); num_files_in_block = 0; ++num_blocks; } -void Corpus::finish() +void EncodingCorpus::finish() { flush_block(); } -size_t Corpus::num_trigrams() const +size_t EncodingCorpus::num_trigrams() const { size_t num = 0; for (unsigned trgm = 0; trgm < NUM_TRIGRAMS; ++trgm) { @@ -306,7 +366,7 @@ size_t Corpus::num_trigrams() const return num; } -string Corpus::get_compressed_dir_times() +string EncodingCorpus::get_compressed_dir_times() { if (!store_dir_times) { return ""; @@ -385,7 +445,7 @@ uint32_t next_prime(uint32_t x) return x; } -unique_ptr create_hashtable(Corpus &corpus, const vector &all_trigrams, uint32_t ht_size, uint32_t num_overflow_slots) +unique_ptr create_hashtable(EncodingCorpus &corpus, const vector &all_trigrams, uint32_t ht_size, uint32_t num_overflow_slots) { unique_ptr ht(new Trigram[ht_size + num_overflow_slots + 1]); // 1 for the sentinel element at the end. for (unsigned i = 0; i < ht_size + num_overflow_slots + 1; ++i) { @@ -395,7 +455,7 @@ unique_ptr create_hashtable(Corpus &corpus, const vector &a } for (uint32_t trgm : all_trigrams) { // We don't know offset yet, so set it to zero. - Trigram to_insert{ trgm, uint32_t(corpus.get_pl_builder(trgm).num_docids), 0 }; + Trigram to_insert{ trgm, uint32_t(corpus.get_pl_builder(trgm).get_num_docids()), 0 }; uint32_t bucket = hash_trigram(trgm, ht_size); unsigned distance = 0; @@ -427,24 +487,26 @@ DatabaseBuilder::DatabaseBuilder(const char *outfile, gid_t owner, int block_siz if (path.empty()) { path = "."; } + int fd = -1; #ifdef O_TMPFILE - int fd = open(path.c_str(), O_WRONLY | O_TMPFILE, 0640); - if (fd == -1) { + fd = open(path.c_str(), O_WRONLY | O_TMPFILE, 0640); + if (fd == -1 && errno != EOPNOTSUPP && errno != EISDIR) { perror(path.c_str()); exit(1); } -#else - temp_filename = string(outfile) + ".XXXXXX"; - int fd = mkstemp(&temp_filename[0]); +#endif if (fd == -1) { - perror(temp_filename.c_str()); - exit(1); - } - if (fchmod(fd, 0640) == -1) { - perror("fchmod"); - exit(1); + temp_filename = string(outfile) + ".XXXXXX"; + fd = mkstemp(&temp_filename[0]); + if (fd == -1) { + perror(temp_filename.c_str()); + exit(1); + } + if (fchmod(fd, 0640) == -1) { + perror("fchmod"); + exit(1); + } } -#endif if (owner != (gid_t)-1) { if (fchown(fd, (uid_t)-1, owner) == -1) { @@ -490,10 +552,10 @@ DatabaseBuilder::DatabaseBuilder(const char *outfile, gid_t owner, int block_siz hdr.conf_block_offset_bytes = 0; } -Corpus *DatabaseBuilder::start_corpus(bool store_dir_times) +DatabaseReceiver *DatabaseBuilder::start_corpus(bool store_dir_times) { corpus_start = steady_clock::now(); - corpus = new Corpus(outfp, block_size, cdict, store_dir_times); + corpus = new EncodingCorpus(outfp, block_size, cdict, store_dir_times); return corpus; } @@ -531,8 +593,8 @@ void DatabaseBuilder::finish_corpus() continue; PostingListBuilder &pl_builder = corpus->get_pl_builder(trgm); pl_builder.finish(); - longest_posting_list = max(longest_posting_list, pl_builder.num_docids); - trigrams += pl_builder.num_docids; + longest_posting_list = max(longest_posting_list, pl_builder.get_num_docids()); + trigrams += pl_builder.get_num_docids(); bytes_for_posting_lists += pl_builder.encoded.size(); } size_t num_trigrams = corpus->num_trigrams(); @@ -573,7 +635,7 @@ void DatabaseBuilder::finish_corpus() continue; } - const string &encoded = corpus->get_pl_builder(hashtable[i].trgm).encoded; + const vector &encoded = corpus->get_pl_builder(hashtable[i].trgm).encoded; offset += encoded.size(); } @@ -587,7 +649,7 @@ void DatabaseBuilder::finish_corpus() if (hashtable[i].num_docids == 0) { continue; } - const string &encoded = corpus->get_pl_builder(hashtable[i].trgm).encoded; + const vector &encoded = corpus->get_pl_builder(hashtable[i].trgm).encoded; fwrite(encoded.data(), encoded.size(), 1, outfp); } @@ -621,22 +683,28 @@ void DatabaseBuilder::finish_corpus() fseek(outfp, 0, SEEK_SET); fwrite(&hdr, sizeof(hdr), 1, outfp); + // This is needed on systems that simulate linkat() by copying + // the contents of the file instead of linking. + fflush(outfp); + + if (!temp_filename.empty()) { + if (rename(temp_filename.c_str(), outfile.c_str()) == -1) { + perror("rename"); + exit(1); + } + } else { #ifdef O_TMPFILE - // Give the file a proper name, making it visible in the file system. - // TODO: It would be nice to be able to do this atomically, like with rename. - unlink(outfile.c_str()); - char procpath[256]; - snprintf(procpath, sizeof(procpath), "/proc/self/fd/%d", fileno(outfp)); - if (linkat(AT_FDCWD, procpath, AT_FDCWD, outfile.c_str(), AT_SYMLINK_FOLLOW) == -1) { - perror("linkat"); - exit(1); - } -#else - if (rename(temp_filename.c_str(), outfile.c_str()) == -1) { - perror("rename"); - exit(1); - } + // Give the file a proper name, making it visible in the file system. + // TODO: It would be nice to be able to do this atomically, like with rename. + unlink(outfile.c_str()); + char procpath[256]; + snprintf(procpath, sizeof(procpath), "/proc/self/fd/%d", fileno(outfp)); + if (linkat(AT_FDCWD, procpath, AT_FDCWD, outfile.c_str(), AT_SYMLINK_FOLLOW) == -1) { + perror("linkat"); + exit(1); + } #endif + } fclose(outfp);