]> git.sesse.net Git - plocate/blobdiff - plocate-build.cpp
Release plocate 1.1.22.
[plocate] / plocate-build.cpp
index e1e2f644ef2ca891f93d48fdaab15e4f681bf418..227eae50b1165a5b4bb469bfaf0a42e5e9fee811 100644 (file)
@@ -1,52 +1,30 @@
+#include "database-builder.h"
 #include "db.h"
-#include "turbopfor-encode.h"
+#include "dprintf.h"
 
 #include <algorithm>
+#include <arpa/inet.h>
 #include <assert.h>
 #include <chrono>
 #include <getopt.h>
 #include <iosfwd>
+#include <locale.h>
 #include <math.h>
 #include <memory>
+#include <random>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <string>
-#include <string_view>
 #include <sys/stat.h>
 #include <utility>
 #include <vector>
-#include <zstd.h>
-
-#define P4NENC_BOUND(n) ((n + 127) / 128 + (n + 32) * sizeof(uint32_t))
-#define dprintf(...)
-//#define dprintf(...) fprintf(stderr, __VA_ARGS__);
-
-#define NUM_TRIGRAMS 16777216
 
 using namespace std;
 using namespace std::chrono;
 
-string zstd_compress(const string &src, string *tempbuf);
-
-constexpr unsigned num_overflow_slots = 16;
-
-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);
-}
+bool use_debug = false;
 
 enum {
        DBE_NORMAL = 0, /* A non-directory file */
@@ -70,162 +48,6 @@ struct db_directory {
        uint8_t pad[4];
 };
 
-class PostingListBuilder {
-public:
-       inline void add_docid(uint32_t docid);
-       void finish();
-
-       string encoded;
-       size_t num_docids = 0;
-
-private:
-       void write_header(uint32_t docid);
-       void append_block();
-
-       vector<uint32_t> pending_deltas;
-
-       uint32_t last_block_end, last_docid = -1;
-};
-
-void PostingListBuilder::add_docid(uint32_t docid)
-{
-       // Deduplicate against the last inserted value, if any.
-       if (docid == last_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;
-}
-
-void PostingListBuilder::finish()
-{
-       if (pending_deltas.empty()) {
-               return;
-       }
-
-       assert(!encoded.empty());  // write_header() should already have run.
-
-       // 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));
-}
-
-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));
-}
-
-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);
-}
-
-class Corpus {
-public:
-       Corpus(FILE *outfp, size_t block_size)
-               : invindex(new PostingListBuilder *[NUM_TRIGRAMS]), outfp(outfp), block_size(block_size)
-       {
-               fill(invindex.get(), invindex.get() + NUM_TRIGRAMS, nullptr);
-       }
-       ~Corpus()
-       {
-               for (unsigned i = 0; i < NUM_TRIGRAMS; ++i) {
-                       delete invindex[i];
-               }
-       }
-
-       void add_file(string filename);
-       void flush_block();
-
-       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;
-       }
-       PostingListBuilder &get_pl_builder(uint32_t trgm)
-       {
-               if (invindex[trgm] == nullptr) {
-                       invindex[trgm] = new PostingListBuilder;
-               }
-               return *invindex[trgm];
-       }
-
-private:
-       unique_ptr<PostingListBuilder *[]> invindex;
-       FILE *outfp;
-       string current_block;
-       string tempbuf;
-       const size_t block_size;
-};
-
-void Corpus::add_file(string filename)
-{
-       ++num_files;
-       if (!current_block.empty()) {
-               current_block.push_back('\0');
-       }
-       current_block += filename;
-       if (++num_files_in_block == block_size) {
-               flush_block();
-       }
-}
-
-void Corpus::flush_block()
-{
-       if (current_block.empty()) {
-               return;
-       }
-
-       uint32_t docid = num_blocks;
-
-       // 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);
-                       }
-               }
-               ptr += s.size() + 1;
-       }
-
-       // Compress and add the filename block.
-       filename_blocks.push_back(ftell(outfp));
-       string compressed = zstd_compress(current_block, &tempbuf);
-       if (fwrite(compressed.data(), compressed.size(), 1, outfp) != 1) {
-               perror("fwrite()");
-               exit(1);
-       }
-
-       current_block.clear();
-       num_files_in_block = 0;
-       ++num_blocks;
-}
-
 string read_cstr(FILE *fp)
 {
        string ret;
@@ -242,7 +64,7 @@ string read_cstr(FILE *fp)
        }
 }
 
-void handle_directory(FILE *fp, Corpus *corpus)
+void handle_directory(FILE *fp, DatabaseReceiver *receiver)
 {
        db_directory dummy;
        if (fread(&dummy, sizeof(dummy), 1, fp) != 1) {
@@ -262,237 +84,100 @@ void handle_directory(FILE *fp, Corpus *corpus)
                int type = getc(fp);
                if (type == DBE_NORMAL) {
                        string filename = read_cstr(fp);
-                       corpus->add_file(dir_path + "/" + filename);
+                       receiver->add_file(dir_path + "/" + filename, unknown_dir_time);
                } else if (type == DBE_DIRECTORY) {
                        string dirname = read_cstr(fp);
-                       corpus->add_file(dir_path + "/" + dirname);
+                       receiver->add_file(dir_path + "/" + dirname, unknown_dir_time);
                } else {
                        return;  // Probably end.
                }
        }
 }
 
-void read_mlocate(const char *filename, Corpus *corpus)
+void read_plaintext(FILE *fp, DatabaseReceiver *receiver)
 {
-       FILE *fp = fopen(filename, "rb");
-       if (fp == nullptr) {
-               perror(filename);
+       if (fseek(fp, 0, SEEK_SET) != 0) {
+               perror("fseek");
                exit(1);
        }
 
-       db_header hdr;
-       if (fread(&hdr, sizeof(hdr), 1, fp) != 1) {
-               perror("short read");
-               exit(1);
-       }
-
-       // TODO: Care about the base path.
-       string path = read_cstr(fp);
        while (!feof(fp)) {
-               handle_directory(fp, corpus);
-       }
-       fclose(fp);
-}
-
-string zstd_compress(const string &src, string *tempbuf)
-{
-       size_t max_size = ZSTD_compressBound(src.size());
-       if (tempbuf->size() < max_size) {
-               tempbuf->resize(max_size);
-       }
-       size_t size = ZSTD_compress(&(*tempbuf)[0], max_size, src.data(), src.size(), /*level=*/6);
-       return string(tempbuf->data(), size);
-}
-
-bool is_prime(uint32_t x)
-{
-       if ((x % 2) == 0 || (x % 3) == 0) {
-               return false;
-       }
-       uint32_t limit = ceil(sqrt(x));
-       for (uint32_t factor = 5; factor <= limit; ++factor) {
-               if ((x % factor) == 0) {
-                       return false;
+               char buf[1024];
+               if (fgets(buf, sizeof(buf), fp) == nullptr) {
+                       break;
                }
-       }
-       return true;
-}
-
-uint32_t next_prime(uint32_t x)
-{
-       if ((x % 2) == 0) {
-               ++x;
-       }
-       while (!is_prime(x)) {
-               x += 2;
-       }
-       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[]> 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) {
-               ht[i].trgm = uint32_t(-1);
-               ht[i].num_docids = 0;
-               ht[i].offset = 0;
-       }
-       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 };
-
-               uint32_t bucket = hash_trigram(trgm, ht_size);
-               unsigned distance = 0;
-               while (ht[bucket].num_docids != 0) {
-                       // Robin Hood hashing; reduces the longest distance by a lot.
-                       unsigned other_distance = bucket - hash_trigram(ht[bucket].trgm, ht_size);
-                       if (distance > other_distance) {
-                               swap(to_insert, ht[bucket]);
-                               distance = other_distance;
-                       }
-
-                       ++bucket, ++distance;
-                       if (distance > num_overflow_slots) {
-                               return nullptr;
+               string s(buf);
+               assert(!s.empty());
+               while (s.back() != '\n' && !feof(fp)) {
+                       // The string was longer than the buffer, so read again.
+                       if (fgets(buf, sizeof(buf), fp) == nullptr) {
+                               break;
                        }
+                       s += buf;
                }
-               ht[bucket] = to_insert;
+               if (!s.empty() && s.back() == '\n')
+                       s.pop_back();
+               receiver->add_file(move(s), unknown_dir_time);
        }
-       return ht;
 }
 
-void do_build(const char *infile, const char *outfile, int block_size)
+void read_mlocate(FILE *fp, DatabaseReceiver *receiver)
 {
-       steady_clock::time_point start __attribute__((unused)) = steady_clock::now();
-
-       umask(0027);
-       FILE *outfp = fopen(outfile, "wb");
-
-       // Write the header.
-       Header hdr;
-       memcpy(hdr.magic, "\0plocate", 8);
-       hdr.version = -1;  // Mark as broken.
-       hdr.hashtable_size = 0;  // Not known yet.
-       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.filename_index_offset_bytes = -1;
-       fwrite(&hdr, sizeof(hdr), 1, outfp);
-
-       Corpus corpus(outfp, block_size);
-
-       read_mlocate(infile, &corpus);
-       if (false) {  // To read a plain text file.
-               FILE *fp = fopen(infile, "r");
-               while (!feof(fp)) {
-                       char buf[1024];
-                       if (fgets(buf, 1024, fp) == nullptr || feof(fp)) {
-                               break;
-                       }
-                       string s(buf);
-                       if (s.back() == '\n')
-                               s.pop_back();
-                       corpus.add_file(move(s));
-               }
-               fclose(fp);
+       if (fseek(fp, 0, SEEK_SET) != 0) {
+               perror("fseek");
+               exit(1);
        }
-       corpus.flush_block();
-       dprintf("Read %zu files from %s\n", corpus.num_files, infile);
-       hdr.num_docids = corpus.filename_blocks.size();
 
-       // Stick an empty block at the end as sentinel.
-       corpus.filename_blocks.push_back(ftell(outfp));
-       const size_t bytes_for_filenames = corpus.filename_blocks.back() - corpus.filename_blocks.front();
-
-       // Write the offsets to the filenames.
-       hdr.filename_index_offset_bytes = ftell(outfp);
-       const size_t bytes_for_filename_index = corpus.filename_blocks.size() * sizeof(uint64_t);
-       fwrite(corpus.filename_blocks.data(), corpus.filename_blocks.size(), sizeof(uint64_t), outfp);
-       corpus.filename_blocks.clear();
-       corpus.filename_blocks.shrink_to_fit();
-
-       // Finish up encoding the posting lists.
-       size_t trigrams = 0, longest_posting_list = 0;
-       size_t bytes_for_posting_lists = 0;
-       for (unsigned trgm = 0; trgm < NUM_TRIGRAMS; ++trgm) {
-               if (!corpus.seen_trigram(trgm))
-                       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;
-               bytes_for_posting_lists += pl_builder.encoded.size();
+       db_header hdr;
+       if (fread(&hdr, sizeof(hdr), 1, fp) != 1) {
+               perror("short read");
+               exit(1);
        }
-       dprintf("%zu files, %zu different trigrams, %zu entries, avg len %.2f, longest %zu\n",
-               corpus.num_files, corpus.invindex.size(), trigrams, double(trigrams) / corpus.invindex.size(), longest_posting_list);
-       dprintf("%zu bytes used for posting lists (%.2f bits/entry)\n", bytes_for_posting_lists, 8 * bytes_for_posting_lists / double(trigrams));
 
-       dprintf("Building posting lists took %.1f ms.\n\n", 1e3 * duration<float>(steady_clock::now() - start).count());
+       // TODO: Care about the base path.
+       string path = read_cstr(fp);
 
-       // Find the used trigrams.
-       vector<uint32_t> all_trigrams;
-       for (unsigned trgm = 0; trgm < NUM_TRIGRAMS; ++trgm) {
-               if (corpus.seen_trigram(trgm)) {
-                       all_trigrams.push_back(trgm);
-               }
+       if (fseek(fp, ntohl(hdr.conf_size), SEEK_CUR) != 0) {
+               perror("skip conf block");
+               exit(1);
        }
 
-       // Create the hash table.
-       unique_ptr<Trigram[]> hashtable;
-       uint32_t ht_size = next_prime(all_trigrams.size());
-       for (;;) {
-               hashtable = create_hashtable(corpus, all_trigrams, ht_size, num_overflow_slots);
-               if (hashtable == nullptr) {
-                       dprintf("Failed creating hash table of size %u, increasing by 5%% and trying again.\n", ht_size);
-                       ht_size = next_prime(ht_size * 1.05);
-               } else {
-                       dprintf("Created hash table of size %u.\n\n", ht_size);
-                       break;
-               }
+       while (!feof(fp)) {
+               handle_directory(fp, receiver);
        }
+}
 
-       // Find the offsets for each posting list.
-       size_t bytes_for_hashtable = (ht_size + num_overflow_slots + 1) * sizeof(Trigram);
-       uint64_t offset = ftell(outfp) + bytes_for_hashtable;
-       for (unsigned i = 0; i < ht_size + num_overflow_slots + 1; ++i) {
-               hashtable[i].offset = offset;  // Needs to be there even for empty slots.
-               if (hashtable[i].num_docids == 0) {
-                       continue;
-               }
-
-               const string &encoded = corpus.get_pl_builder(hashtable[i].trgm).encoded;
-               offset += encoded.size();
+void do_build(const char *infile, const char *outfile, int block_size, bool plaintext, bool check_visibility)
+{
+       FILE *infp = fopen(infile, "rb");
+       if (infp == nullptr) {
+               perror(infile);
+               exit(1);
        }
 
-       // Write the hash table.
-       hdr.hash_table_offset_bytes = ftell(outfp);
-       hdr.hashtable_size = ht_size;
-       fwrite(hashtable.get(), ht_size + num_overflow_slots + 1, sizeof(Trigram), outfp);
-
-       // Write the actual posting lists.
-       for (unsigned i = 0; i < ht_size + num_overflow_slots + 1; ++i) {
-               if (hashtable[i].num_docids == 0) {
-                       continue;
-               }
-               const string &encoded = corpus.get_pl_builder(hashtable[i].trgm).encoded;
-               fwrite(encoded.data(), encoded.size(), 1, outfp);
+       // Train the dictionary by sampling real blocks.
+       // The documentation for ZDICT_trainFromBuffer() claims that a reasonable
+       // dictionary size is ~100 kB, but 1 kB seems to actually compress better for us,
+       // and decompress just as fast.
+       DictionaryBuilder builder(/*blocks_to_keep=*/1000, block_size);
+       if (plaintext) {
+               read_plaintext(infp, &builder);
+       } else {
+               read_mlocate(infp, &builder);
        }
+       string dictionary = builder.train(1024);
 
-       // Rewind, and write the updated header.
-       hdr.version = 0;
-       fseek(outfp, 0, SEEK_SET);
-       fwrite(&hdr, sizeof(hdr), 1, outfp);
-       fclose(outfp);
-
-       size_t total_bytes __attribute__((unused)) = (bytes_for_hashtable + bytes_for_posting_lists + bytes_for_filename_index + bytes_for_filenames);
+       DatabaseBuilder db(outfile, /*owner=*/-1, block_size, dictionary, check_visibility);
+       DatabaseReceiver *corpus = db.start_corpus(/*store_dir_times=*/false);
+       if (plaintext) {
+               read_plaintext(infp, corpus);
+       } else {
+               read_mlocate(infp, corpus);
+       }
+       fclose(infp);
 
-       dprintf("Block size:     %7d files\n", block_size);
-       dprintf("Hash table:     %'7.1f MB\n", bytes_for_hashtable / 1048576.0);
-       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);
-       dprintf("Total:          %'7.1f MB\n", total_bytes / 1048576.0);
-       dprintf("\n");
+       dprintf("Read %zu files from %s\n", corpus->num_files_seen(), infile);
+       db.finish_corpus();
 }
 
 void usage()
@@ -504,34 +189,54 @@ void usage()
                "Normally, the destination should be /var/lib/mlocate/plocate.db.\n"
                "\n"
                "  -b, --block-size SIZE  number of filenames to store in each block (default 32)\n"
+               "  -p, --plaintext        input is a plaintext file, not an mlocate database\n"
+               "  -l, --require-visibility FLAG  check visibility before reporting files\n"
                "      --help             print this help\n"
                "      --version          print version information\n");
 }
 
 void version()
 {
-       printf("plocate-build %s\n", PLOCATE_VERSION);
+       printf("plocate-build %s\n", PACKAGE_VERSION);
        printf("Copyright 2020 Steinar H. Gunderson\n");
        printf("License GPLv2+: GNU GPL version 2 or later <https://gnu.org/licenses/gpl.html>.\n");
        printf("This is free software: you are free to change and redistribute it.\n");
        printf("There is NO WARRANTY, to the extent permitted by law.\n");
 }
 
+bool parse_bool(const string &str, bool *result)
+{
+       if (str == "0" || str == "no") {
+               *result = false;
+               return true;
+       }
+       if (str == "1" || str == "yes") {
+               *result = true;
+               return true;
+       }
+       return false;
+}
+
 int main(int argc, char **argv)
 {
        static const struct option long_options[] = {
                { "block-size", required_argument, 0, 'b' },
+               { "plaintext", no_argument, 0, 'p' },
+               { "require-visibility", required_argument, 0, 'l' },
                { "help", no_argument, 0, 'h' },
                { "version", no_argument, 0, 'V' },
+               { "debug", no_argument, 0, 'D' },  // Not documented.
                { 0, 0, 0, 0 }
        };
 
        int block_size = 32;
+       bool plaintext = false;
+       bool check_visibility = true;
 
        setlocale(LC_ALL, "");
        for (;;) {
                int option_index = 0;
-               int c = getopt_long(argc, argv, "b:hV", long_options, &option_index);
+               int c = getopt_long(argc, argv, "b:hpl:VD", long_options, &option_index);
                if (c == -1) {
                        break;
                }
@@ -539,12 +244,25 @@ int main(int argc, char **argv)
                case 'b':
                        block_size = atoi(optarg);
                        break;
+               case 'p':
+                       plaintext = true;
+                       break;
+               case 'l':
+                       if (!parse_bool(optarg, &check_visibility) != 0) {
+                               fprintf(stderr, "plocate-build: invalid value `%s' for --%s\n",
+                                        optarg, "require-visibility");
+                               exit(EXIT_FAILURE);
+                       }
+                       break;
                case 'h':
                        usage();
                        exit(0);
-               case 'v':
+               case 'V':
                        version();
                        exit(0);
+               case 'D':
+                       use_debug = true;
+                       break;
                default:
                        exit(1);
                }
@@ -555,6 +273,6 @@ int main(int argc, char **argv)
                exit(1);
        }
 
-       do_build(argv[optind], argv[optind + 1], block_size);
+       do_build(argv[optind], argv[optind + 1], block_size, plaintext, check_visibility);
        exit(EXIT_SUCCESS);
 }