+#include "database-builder.h"
#include "db.h"
#include "dprintf.h"
-#include "turbopfor-encode.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 <stdlib.h>
#include <string.h>
#include <string>
-#include <string_view>
#include <sys/stat.h>
#include <utility>
#include <vector>
-#include <zdict.h>
-#include <zstd.h>
-
-#define P4NENC_BOUND(n) ((n + 127) / 128 + (n + 32) * sizeof(uint32_t))
-
-#define NUM_TRIGRAMS 16777216
using namespace std;
using namespace std::chrono;
-string zstd_compress(const string &src, ZSTD_CDict *cdict, string *tempbuf);
-
-constexpr unsigned num_overflow_slots = 16;
bool use_debug = false;
-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);
-}
-
enum {
DBE_NORMAL = 0, /* A non-directory file */
DBE_DIRECTORY = 1, /* A 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 DatabaseReceiver {
-public:
- virtual ~DatabaseReceiver() = default;
- virtual void add_file(string filename) = 0;
- virtual void flush_block() = 0;
-};
-
-class DictionaryBuilder : public DatabaseReceiver {
-public:
- DictionaryBuilder(size_t blocks_to_keep, size_t block_size)
- : blocks_to_keep(blocks_to_keep), block_size(block_size) {}
- void add_file(string filename) override;
- void flush_block() override;
- string train(size_t buf_size);
-
-private:
- const size_t blocks_to_keep, block_size;
- string current_block;
- uint64_t block_num = 0;
- size_t num_files_in_block = 0;
-
- std::mt19937 reservoir_rand{ 1234 }; // Fixed seed for reproducibility.
- bool keep_current_block = true;
- int64_t slot_for_current_block = -1;
-
- vector<string> sampled_blocks;
- vector<size_t> lengths;
-};
-
-void DictionaryBuilder::add_file(string filename)
-{
- if (keep_current_block) { // Only bother saving the filenames if we're actually keeping the block.
- if (!current_block.empty()) {
- current_block.push_back('\0');
- }
- current_block += filename;
- }
- if (++num_files_in_block == block_size) {
- flush_block();
- }
-}
-
-void DictionaryBuilder::flush_block()
-{
- if (keep_current_block) {
- if (slot_for_current_block == -1) {
- lengths.push_back(current_block.size());
- sampled_blocks.push_back(move(current_block));
- } else {
- lengths[slot_for_current_block] = current_block.size();
- sampled_blocks[slot_for_current_block] = move(current_block);
- }
- }
- current_block.clear();
- num_files_in_block = 0;
- ++block_num;
-
- if (block_num < blocks_to_keep) {
- keep_current_block = true;
- slot_for_current_block = -1;
- } else {
- // Keep every block with equal probability (reservoir sampling).
- uint64_t idx = uniform_int_distribution<uint64_t>(0, block_num)(reservoir_rand);
- keep_current_block = (idx < blocks_to_keep);
- slot_for_current_block = idx;
- }
-}
-
-string DictionaryBuilder::train(size_t buf_size)
-{
- string dictionary_buf;
- sort(sampled_blocks.begin(), sampled_blocks.end()); // Seemingly important for decompression speed.
- for (const string &block : sampled_blocks) {
- dictionary_buf += block;
- }
-
- string buf;
- buf.resize(buf_size);
- size_t ret = ZDICT_trainFromBuffer(&buf[0], buf_size, dictionary_buf.data(), lengths.data(), lengths.size());
- dprintf("Sampled %zu bytes in %zu blocks, built a dictionary of size %zu\n", dictionary_buf.size(), lengths.size(), ret);
- buf.resize(ret);
-
- sampled_blocks.clear();
- lengths.clear();
-
- return buf;
-}
-
-class Corpus : public DatabaseReceiver {
-public:
- Corpus(FILE *outfp, size_t block_size, ZSTD_CDict *cdict)
- : invindex(new PostingListBuilder *[NUM_TRIGRAMS]), outfp(outfp), block_size(block_size), cdict(cdict)
- {
- fill(invindex.get(), invindex.get() + NUM_TRIGRAMS, nullptr);
- }
- ~Corpus() override
- {
- for (unsigned i = 0; i < NUM_TRIGRAMS; ++i) {
- delete invindex[i];
- }
- }
-
- void add_file(string filename) override;
- void flush_block() override;
-
- 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];
- }
- size_t num_trigrams() const;
-
-private:
- unique_ptr<PostingListBuilder *[]> invindex;
- FILE *outfp;
- string current_block;
- string tempbuf;
- const size_t block_size;
- ZSTD_CDict *cdict;
-};
-
-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, cdict, &tempbuf);
- if (fwrite(compressed.data(), compressed.size(), 1, outfp) != 1) {
- perror("fwrite()");
- exit(1);
- }
-
- current_block.clear();
- num_files_in_block = 0;
- ++num_blocks;
-}
-
-size_t Corpus::num_trigrams() const
-{
- size_t num = 0;
- for (unsigned trgm = 0; trgm < NUM_TRIGRAMS; ++trgm) {
- if (invindex[trgm] != nullptr) {
- ++num;
- }
- }
- return num;
-}
-
string read_cstr(FILE *fp)
{
string ret;
int type = getc(fp);
if (type == DBE_NORMAL) {
string filename = read_cstr(fp);
- receiver->add_file(dir_path + "/" + filename);
+ receiver->add_file(dir_path + "/" + filename, unknown_dir_time);
} else if (type == DBE_DIRECTORY) {
string dirname = read_cstr(fp);
- receiver->add_file(dir_path + "/" + dirname);
+ receiver->add_file(dir_path + "/" + dirname, unknown_dir_time);
} else {
return; // Probably end.
}
}
}
-void read_mlocate(const char *filename, DatabaseReceiver *receiver)
+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, receiver);
+ char buf[1024];
+ if (fgets(buf, sizeof(buf), fp) == nullptr) {
+ break;
+ }
+ 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;
+ }
+ if (!s.empty() && s.back() == '\n')
+ s.pop_back();
+ receiver->add_file(move(s), unknown_dir_time);
}
- fclose(fp);
}
-string zstd_compress(const string &src, ZSTD_CDict *cdict, string *tempbuf)
+void read_mlocate(FILE *fp, DatabaseReceiver *receiver)
{
- static ZSTD_CCtx *ctx = nullptr;
- if (ctx == nullptr) {
- ctx = ZSTD_createCCtx();
- }
-
- size_t max_size = ZSTD_compressBound(src.size());
- if (tempbuf->size() < max_size) {
- tempbuf->resize(max_size);
- }
- size_t size;
- if (cdict == nullptr) {
- size = ZSTD_compressCCtx(ctx, &(*tempbuf)[0], max_size, src.data(), src.size(), /*level=*/6);
- } else {
- size = ZSTD_compress_usingCDict(ctx, &(*tempbuf)[0], max_size, src.data(), src.size(), cdict);
+ if (fseek(fp, 0, SEEK_SET) != 0) {
+ perror("fseek");
+ exit(1);
}
- 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;
- }
+ db_header hdr;
+ if (fread(&hdr, sizeof(hdr), 1, fp) != 1) {
+ perror("short read");
+ exit(1);
}
- return true;
-}
-uint32_t next_prime(uint32_t x)
-{
- if ((x % 2) == 0) {
- ++x;
- }
- while (!is_prime(x)) {
- x += 2;
- }
- return x;
-}
+ // TODO: Care about the base path.
+ string path = read_cstr(fp);
-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;
+ if (fseek(fp, ntohl(hdr.conf_size), SEEK_CUR) != 0) {
+ perror("skip conf block");
+ exit(1);
}
- 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;
- }
- }
- ht[bucket] = to_insert;
+ while (!feof(fp)) {
+ handle_directory(fp, receiver);
}
- return ht;
}
-void do_build(const char *infile, const char *outfile, int block_size)
+void do_build(const char *infile, const char *outfile, int block_size, bool plaintext)
{
- steady_clock::time_point start __attribute__((unused)) = steady_clock::now();
-
- umask(0027);
- FILE *outfp = fopen(outfile, "wb");
- if (outfp == nullptr) {
- perror(outfile);
+ FILE *infp = fopen(infile, "rb");
+ if (infp == nullptr) {
+ perror(infile);
exit(1);
}
- // 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.max_version = 1;
- hdr.filename_index_offset_bytes = -1;
- hdr.zstd_dictionary_length_bytes = -1;
- fwrite(&hdr, sizeof(hdr), 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);
- read_mlocate(infile, &builder);
- string dictionary = builder.train(1024);
- ZSTD_CDict *cdict = ZSTD_createCDict(dictionary.data(), dictionary.size(), /*level=*/6);
-
- hdr.zstd_dictionary_offset_bytes = ftell(outfp);
- fwrite(dictionary.data(), dictionary.size(), 1, outfp);
- hdr.zstd_dictionary_length_bytes = dictionary.size();
-
- Corpus corpus(outfp, block_size, cdict);
- 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);
- }
- 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();
- }
- size_t num_trigrams = corpus.num_trigrams();
- dprintf("%zu files, %zu different trigrams, %zu entries, avg len %.2f, longest %zu\n",
- corpus.num_files, num_trigrams, trigrams, double(trigrams) / num_trigrams, 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());
-
- // 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);
- }
- }
-
- // 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;
- }
- }
-
- // 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();
+ if (plaintext) {
+ read_plaintext(infp, &builder);
+ } else {
+ read_mlocate(infp, &builder);
}
+ string dictionary = builder.train(1024);
- // 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);
+ DatabaseBuilder db(outfile, /*owner=*/-1, block_size, dictionary, /*check_visibility=*/true);
+ DatabaseReceiver *corpus = db.start_corpus(/*store_dir_times=*/false);
+ if (plaintext) {
+ read_plaintext(infp, corpus);
+ } else {
+ read_mlocate(infp, corpus);
}
+ fclose(infp);
- // Rewind, and write the updated header.
- hdr.version = 1;
- 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);
-
- dprintf("Block size: %7d files\n", block_size);
- dprintf("Dictionary: %'7.1f MB\n", dictionary.size() / 1048576.0);
- 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()
"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"
" --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");
{
static const struct option long_options[] = {
{ "block-size", required_argument, 0, 'b' },
+ { "plaintext", no_argument, 0, 'p' },
{ "help", no_argument, 0, 'h' },
{ "version", no_argument, 0, 'V' },
{ "debug", no_argument, 0, 'D' }, // Not documented.
};
int block_size = 32;
+ bool plaintext = false;
setlocale(LC_ALL, "");
for (;;) {
int option_index = 0;
- int c = getopt_long(argc, argv, "b:hVD", long_options, &option_index);
+ int c = getopt_long(argc, argv, "b:hpVD", long_options, &option_index);
if (c == -1) {
break;
}
case 'b':
block_size = atoi(optarg);
break;
+ case 'p':
+ plaintext = true;
+ break;
case 'h':
usage();
exit(0);
exit(1);
}
- do_build(argv[optind], argv[optind + 1], block_size);
+ do_build(argv[optind], argv[optind + 1], block_size, plaintext);
exit(EXIT_SUCCESS);
}