]> git.sesse.net Git - plocate/blobdiff - database-builder.cpp
Release plocate 1.1.22.
[plocate] / database-builder.cpp
index 49f09b469c201039a854d97422b2c527d0e56689..f9dfb715391b3be7c4c521710d48f86b3b10795b 100644 (file)
@@ -5,12 +5,16 @@
 
 #include <algorithm>
 #include <assert.h>
+#ifdef HAS_ENDIAN_H
+#include <endian.h>
+#endif
 #include <fcntl.h>
 #include <string.h>
 #include <string_view>
 #include <sys/stat.h>
 #include <sys/time.h>
 #include <sys/types.h>
+#include <unistd.h>
 #include <zdict.h>
 #include <zstd.h>
 
@@ -25,29 +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<unsigned char> 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);
@@ -55,7 +49,8 @@ private:
 
        vector<uint32_t> 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)
@@ -65,22 +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()
@@ -94,7 +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<char *>(buf), reinterpret_cast<char *>(end));
+       encoded.insert(encoded.end(), buf, end);
+
+       num_docids += pending_deltas.size();
+       pending_deltas.clear();
 }
 
 void PostingListBuilder::append_block()
@@ -102,17 +98,17 @@ 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<char *>(buf), reinterpret_cast<char *>(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<char *>(buf), end - buf);
+       encoded.insert(encoded.end(), buf, end);
 }
 
-void DictionaryBuilder::add_file(string filename)
+void DictionaryBuilder::add_file(string filename, dir_time)
 {
        if (keep_current_block) {  // Only bother saving the filenames if we're actually keeping the block.
                if (!current_block.empty()) {
@@ -162,7 +158,7 @@ string DictionaryBuilder::train(size_t buf_size)
        string buf;
        buf.resize(buf_size);
        size_t ret = ZDICT_trainFromBuffer(&buf[0], buf_size, dictionary_buf.data(), lengths.data(), lengths.size());
-       if (ret == size_t(-1)) {
+       if (ZDICT_isError(ret)) {
                return "";
        }
        dprintf("Sampled %zu bytes in %zu blocks, built a dictionary of size %zu\n", dictionary_buf.size(), lengths.size(), ret);
@@ -174,28 +170,75 @@ string DictionaryBuilder::train(size_t buf_size)
        return buf;
 }
 
-Corpus::Corpus(FILE *outfp, size_t block_size, ZSTD_CDict *cdict)
-       : invindex(new PostingListBuilder *[NUM_TRIGRAMS]), outfp(outfp), block_size(block_size), 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<uint64_t> 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<PostingListBuilder *[]> 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) {
+               dir_time_ctx = ZSTD_createCStream();
+               ZSTD_initCStream(dir_time_ctx, /*level=*/6);
+       }
 }
 
-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)
+void EncodingCorpus::add_file(string filename, dir_time dt)
 {
        ++num_files;
        if (!current_block.empty()) {
@@ -205,9 +248,53 @@ void Corpus::add_file(string filename)
        if (++num_files_in_block == block_size) {
                flush_block();
        }
+
+       if (store_dir_times) {
+               if (dt.sec == -1) {
+                       // Not a directory.
+                       dir_times.push_back('\0');
+               } else {
+                       dir_times.push_back('\1');
+                       dir_times.append(reinterpret_cast<char *>(&dt.sec), sizeof(dt.sec));
+                       dir_times.append(reinterpret_cast<char *>(&dt.nsec), sizeof(dt.nsec));
+               }
+               compress_dir_times(/*allowed_slop=*/4096);
+       }
 }
 
-void Corpus::flush_block()
+void EncodingCorpus::compress_dir_times(size_t allowed_slop)
+{
+       while (dir_times.size() >= allowed_slop) {
+               size_t old_size = dir_times_compressed.size();
+               dir_times_compressed.resize(old_size + 4096);
+
+               ZSTD_outBuffer outbuf;
+               outbuf.dst = dir_times_compressed.data() + old_size;
+               outbuf.size = 4096;
+               outbuf.pos = 0;
+
+               ZSTD_inBuffer inbuf;
+               inbuf.src = dir_times.data();
+               inbuf.size = dir_times.size();
+               inbuf.pos = 0;
+
+               int ret = ZSTD_compressStream(dir_time_ctx, &outbuf, &inbuf);
+               if (ret < 0) {
+                       fprintf(stderr, "ZSTD_compressStream() failed\n");
+                       exit(1);
+               }
+
+               dir_times_compressed.resize(old_size + outbuf.pos);
+               dir_times.erase(dir_times.begin(), dir_times.begin() + inbuf.pos);
+
+               if (outbuf.pos == 0 && inbuf.pos == 0) {
+                       // Nothing happened (not enough data?), try again later.
+                       return;
+               }
+       }
+}
+
+void EncodingCorpus::flush_block()
 {
        if (current_block.empty()) {
                return;
@@ -217,39 +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();
-       string tempbuf;
-       string compressed = zstd_compress(directory_data, nullptr, &tempbuf);
-       fprintf(stderr, "dirdata: %zu bytes (compressed: %zu)\n", directory_data.size(), compressed.size());
 }
 
-size_t Corpus::num_trigrams() const
+size_t EncodingCorpus::num_trigrams() const
 {
        size_t num = 0;
        for (unsigned trgm = 0; trgm < NUM_TRIGRAMS; ++trgm) {
@@ -260,6 +366,40 @@ size_t Corpus::num_trigrams() const
        return num;
 }
 
+string EncodingCorpus::get_compressed_dir_times()
+{
+       if (!store_dir_times) {
+               return "";
+       }
+       compress_dir_times(/*allowed_slop=*/0);
+       assert(dir_times.empty());
+
+       for (;;) {
+               size_t old_size = dir_times_compressed.size();
+               dir_times_compressed.resize(old_size + 4096);
+
+               ZSTD_outBuffer outbuf;
+               outbuf.dst = dir_times_compressed.data() + old_size;
+               outbuf.size = 4096;
+               outbuf.pos = 0;
+
+               int ret = ZSTD_endStream(dir_time_ctx, &outbuf);
+               if (ret < 0) {
+                       fprintf(stderr, "ZSTD_compressStream() failed\n");
+                       exit(1);
+               }
+
+               dir_times_compressed.resize(old_size + outbuf.pos);
+
+               if (ret == 0) {
+                       // All done.
+                       break;
+               }
+       }
+
+       return dir_times_compressed;
+}
+
 string zstd_compress(const string &src, ZSTD_CDict *cdict, string *tempbuf)
 {
        static ZSTD_CCtx *ctx = nullptr;
@@ -305,7 +445,7 @@ uint32_t next_prime(uint32_t x)
        return x;
 }
 
-unique_ptr<Trigram[]> create_hashtable(Corpus &corpus, const vector<uint32_t> &all_trigrams, uint32_t ht_size, uint32_t num_overflow_slots)
+unique_ptr<Trigram[]> create_hashtable(EncodingCorpus &corpus, const vector<uint32_t> &all_trigrams, uint32_t ht_size, uint32_t num_overflow_slots)
 {
        unique_ptr<Trigram[]> 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) {
@@ -315,7 +455,7 @@ unique_ptr<Trigram[]> create_hashtable(Corpus &corpus, const vector<uint32_t> &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;
@@ -337,11 +477,45 @@ unique_ptr<Trigram[]> create_hashtable(Corpus &corpus, const vector<uint32_t> &a
        return ht;
 }
 
-DatabaseBuilder::DatabaseBuilder(const char *outfile, int block_size, string dictionary)
-       : block_size(block_size)
+DatabaseBuilder::DatabaseBuilder(const char *outfile, gid_t owner, int block_size, string dictionary, bool check_visibility)
+       : outfile(outfile), block_size(block_size)
 {
        umask(0027);
-       outfp = fopen(outfile, "wb");
+
+       string path = outfile;
+       path.resize(path.find_last_of('/') + 1);
+       if (path.empty()) {
+               path = ".";
+       }
+       int fd = -1;
+#ifdef O_TMPFILE
+       fd = open(path.c_str(), O_WRONLY | O_TMPFILE, 0640);
+       if (fd == -1 && errno != EOPNOTSUPP && errno != EISDIR) {
+               perror(path.c_str());
+               exit(1);
+       }
+#endif
+       if (fd == -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);
+               }
+       }
+
+       if (owner != (gid_t)-1) {
+               if (fchown(fd, (uid_t)-1, owner) == -1) {
+                       perror("fchown");
+                       exit(1);
+               }
+       }
+
+       outfp = fdopen(fd, "wb");
        if (outfp == nullptr) {
                perror(outfile);
                exit(1);
@@ -354,9 +528,10 @@ DatabaseBuilder::DatabaseBuilder(const char *outfile, int block_size, string dic
        hdr.extra_ht_slots = num_overflow_slots;
        hdr.num_docids = 0;
        hdr.hash_table_offset_bytes = -1;  // We don't know these offsets yet.
-       hdr.max_version = 1;
+       hdr.max_version = 2;
        hdr.filename_index_offset_bytes = -1;
        hdr.zstd_dictionary_length_bytes = -1;
+       hdr.check_visibility = check_visibility;
        fwrite(&hdr, sizeof(hdr), 1, outfp);
 
        if (dictionary.empty()) {
@@ -368,15 +543,32 @@ DatabaseBuilder::DatabaseBuilder(const char *outfile, int block_size, string dic
                hdr.zstd_dictionary_length_bytes = dictionary.size();
                cdict = ZSTD_createCDict(dictionary.data(), dictionary.size(), /*level=*/6);
        }
+
+       hdr.directory_data_length_bytes = 0;
+       hdr.directory_data_offset_bytes = 0;
+       hdr.next_zstd_dictionary_length_bytes = 0;
+       hdr.next_zstd_dictionary_offset_bytes = 0;
+       hdr.conf_block_length_bytes = 0;
+       hdr.conf_block_offset_bytes = 0;
 }
 
-Corpus *DatabaseBuilder::start_corpus()
+DatabaseReceiver *DatabaseBuilder::start_corpus(bool store_dir_times)
 {
        corpus_start = steady_clock::now();
-       corpus = new Corpus(outfp, block_size, cdict);
+       corpus = new EncodingCorpus(outfp, block_size, cdict, store_dir_times);
        return corpus;
 }
 
+void DatabaseBuilder::set_next_dictionary(std::string next_dictionary)
+{
+       this->next_dictionary = move(next_dictionary);
+}
+
+void DatabaseBuilder::set_conf_block(std::string conf_block)
+{
+       this->conf_block = move(conf_block);
+}
+
 void DatabaseBuilder::finish_corpus()
 {
        corpus->finish();
@@ -401,8 +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();
@@ -443,7 +635,7 @@ void DatabaseBuilder::finish_corpus()
                        continue;
                }
 
-               const string &encoded = corpus->get_pl_builder(hashtable[i].trgm).encoded;
+               const vector<unsigned char> &encoded = corpus->get_pl_builder(hashtable[i].trgm).encoded;
                offset += encoded.size();
        }
 
@@ -457,17 +649,66 @@ void DatabaseBuilder::finish_corpus()
                if (hashtable[i].num_docids == 0) {
                        continue;
                }
-               const string &encoded = corpus->get_pl_builder(hashtable[i].trgm).encoded;
+               const vector<unsigned char> &encoded = corpus->get_pl_builder(hashtable[i].trgm).encoded;
                fwrite(encoded.data(), encoded.size(), 1, outfp);
        }
 
+       // Finally, write the directory times (for updatedb).
+       string compressed_dir_times = corpus->get_compressed_dir_times();
+       size_t bytes_for_compressed_dir_times = 0;
+       if (!compressed_dir_times.empty()) {
+               hdr.directory_data_offset_bytes = ftell(outfp);
+               hdr.directory_data_length_bytes = compressed_dir_times.size();
+               fwrite(compressed_dir_times.data(), compressed_dir_times.size(), 1, outfp);
+               bytes_for_compressed_dir_times = compressed_dir_times.size();
+               compressed_dir_times.clear();
+       }
+
+       // Write the recommended dictionary for next update.
+       if (!next_dictionary.empty()) {
+               hdr.next_zstd_dictionary_offset_bytes = ftell(outfp);
+               hdr.next_zstd_dictionary_length_bytes = next_dictionary.size();
+               fwrite(next_dictionary.data(), next_dictionary.size(), 1, outfp);
+       }
+
+       // And the configuration block.
+       if (!conf_block.empty()) {
+               hdr.conf_block_offset_bytes = ftell(outfp);
+               hdr.conf_block_length_bytes = conf_block.size();
+               fwrite(conf_block.data(), conf_block.size(), 1, outfp);
+       }
+
        // Rewind, and write the updated header.
        hdr.version = 1;
        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);
+               }
+#endif
+       }
+
        fclose(outfp);
 
-       size_t total_bytes = (bytes_for_hashtable + bytes_for_posting_lists + bytes_for_filename_index + bytes_for_filenames);
+       size_t total_bytes = (bytes_for_hashtable + bytes_for_posting_lists + bytes_for_filename_index + bytes_for_filenames + bytes_for_compressed_dir_times);
 
        dprintf("Block size:     %7d files\n", block_size);
        dprintf("Dictionary:     %'7.1f MB\n", hdr.zstd_dictionary_length_bytes / 1048576.0);
@@ -475,6 +716,9 @@ void DatabaseBuilder::finish_corpus()
        dprintf("Posting lists:  %'7.1f MB\n", bytes_for_posting_lists / 1048576.0);
        dprintf("Filename index: %'7.1f MB\n", bytes_for_filename_index / 1048576.0);
        dprintf("Filenames:      %'7.1f MB\n", bytes_for_filenames / 1048576.0);
+       if (bytes_for_compressed_dir_times != 0) {
+               dprintf("Modify times:   %'7.1f MB\n", bytes_for_compressed_dir_times / 1048576.0);
+       }
        dprintf("Total:          %'7.1f MB\n", total_bytes / 1048576.0);
        dprintf("\n");
 }