+#include "db.h"
+#include "io_uring_engine.h"
+#include "vp4.h"
+
+#include <algorithm>
+#include <arpa/inet.h>
+#include <assert.h>
+#include <chrono>
+#include <endian.h>
+#include <fcntl.h>
+#include <functional>
+#include <getopt.h>
+#include <limits.h>
+#include <memory>
#include <stdio.h>
#include <string.h>
-#include <algorithm>
-#include <unordered_map>
#include <string>
-#include <vector>
-#include <chrono>
#include <unistd.h>
-#include <fcntl.h>
-#include <sys/mman.h>
-#include <arpa/inet.h>
-#include <endian.h>
+#include <unordered_map>
+#include <vector>
#include <zstd.h>
-#include "vp4.h"
-
-#define P4NENC_BOUND(n) ((n+127)/128+(n+32)*sizeof(uint32_t))
-
using namespace std;
using namespace std::chrono;
#define dprintf(...)
//#define dprintf(...) fprintf(stderr, __VA_ARGS__);
-
+
+#include "turbopfor.h"
+
+const char *dbpath = "/var/lib/mlocate/plocate.db";
+bool print_nul = false;
+
+class Serializer {
+public:
+ bool ready_to_print(int seq) { return next_seq == seq; }
+ void print_delayed(int seq, const vector<string> msg);
+ void release_current();
+
+private:
+ int next_seq = 0;
+ struct Element {
+ int seq;
+ vector<string> msg;
+
+ bool operator<(const Element &other) const
+ {
+ return seq > other.seq;
+ }
+ };
+ priority_queue<Element> pending;
+};
+
+void Serializer::print_delayed(int seq, const vector<string> msg)
+{
+ pending.push(Element{ seq, move(msg) });
+}
+
+void Serializer::release_current()
+{
+ ++next_seq;
+
+ // See if any delayed prints can now be dealt with.
+ while (!pending.empty() && pending.top().seq == next_seq) {
+ for (const string &msg : pending.top().msg) {
+ if (print_nul) {
+ printf("%s%c", msg.c_str(), 0);
+ } else {
+ printf("%s\n", msg.c_str());
+ }
+ }
+ pending.pop();
+ ++next_seq;
+ }
+}
+
static inline uint32_t read_unigram(const string &s, size_t idx)
{
if (idx < s.size()) {
static inline uint32_t read_trigram(const string &s, size_t start)
{
- return read_unigram(s, start) |
- (read_unigram(s, start + 1) << 8) |
+ return read_unigram(s, start) | (read_unigram(s, start + 1) << 8) |
(read_unigram(s, start + 2) << 16);
}
-bool has_access(const char *filename, unordered_map<string, bool> *access_rx_cache)
+bool has_access(const char *filename,
+ unordered_map<string, bool> *access_rx_cache)
{
const char *end = strchr(filename + 1, '/');
while (end != nullptr) {
end = strchr(end + 1, '/');
}
-#if 0
- // Check for rx first in the cache; if that isn't true, check R_OK uncached.
- // This is roughly the same thing as mlocate does.
- auto it = access_rx_cache->find(filename);
- if (it != access_rx_cache->end() && it->second) {
- return true;
- }
-
- return access(filename, R_OK) == 0;
-#endif
return true;
}
-struct Trigram {
- uint32_t trgm;
- uint32_t num_docids;
- uint64_t offset;
-};
-
class Corpus {
public:
- Corpus(int fd);
+ Corpus(int fd, IOUringEngine *engine);
~Corpus();
- const Trigram *find_trigram(uint32_t trgm) const;
- const unsigned char *get_compressed_posting_list(const Trigram *trigram) const;
- string_view get_compressed_filename_block(uint32_t docid) const;
+ void find_trigram(uint32_t trgm, function<void(const Trigram *trgmptr, size_t len)> cb);
+ void get_compressed_filename_block(uint32_t docid, function<void(string)> cb) const;
+ size_t get_num_filename_blocks() const;
+ off_t offset_for_block(uint32_t docid) const
+ {
+ return hdr.filename_index_offset_bytes + docid * sizeof(uint64_t);
+ }
-private:
+public:
const int fd;
- off_t len;
- const char *data;
- const uint64_t *filename_offsets;
- const Trigram *trgm_begin, *trgm_end;
+ IOUringEngine *const engine;
+
+ Header hdr;
};
-Corpus::Corpus(int fd)
- : fd(fd)
+Corpus::Corpus(int fd, IOUringEngine *engine)
+ : fd(fd), engine(engine)
{
- len = lseek(fd, 0, SEEK_END);
- if (len == -1) {
- perror("lseek");
+ // Enable to test cold-cache behavior (except for access()).
+ if (false) {
+ off_t len = lseek(fd, 0, SEEK_END);
+ if (len == -1) {
+ perror("lseek");
+ exit(1);
+ }
+ posix_fadvise(fd, 0, len, POSIX_FADV_DONTNEED);
+ }
+
+ complete_pread(fd, &hdr, sizeof(hdr), /*offset=*/0);
+ if (memcmp(hdr.magic, "\0plocate", 8) != 0) {
+ fprintf(stderr, "plocate.db is corrupt or an old version; please rebuild it.\n");
exit(1);
}
- data = (char *)mmap(nullptr, len, PROT_READ, MAP_SHARED, fd, /*offset=*/0);
- if (data == MAP_FAILED) {
- perror("mmap");
+ if (hdr.version != 0) {
+ fprintf(stderr, "plocate.db has version %u, expected 0; please rebuild it.\n", hdr.version);
exit(1);
}
-
- uint64_t num_trigrams = *(const uint64_t *)data;
- uint64_t filename_index_offset = *(const uint64_t *)(data + sizeof(uint64_t));
- filename_offsets = (const uint64_t *)(data + filename_index_offset);
-
- trgm_begin = (Trigram *)(data + sizeof(uint64_t) * 2);
- trgm_end = trgm_begin + num_trigrams;
}
Corpus::~Corpus()
{
- munmap((void *)data, len);
close(fd);
}
-const Trigram *Corpus::find_trigram(uint32_t trgm) const
+void Corpus::find_trigram(uint32_t trgm, function<void(const Trigram *trgmptr, size_t len)> cb)
{
- const Trigram *trgmptr = lower_bound(trgm_begin, trgm_end, trgm, [](const Trigram &trgm, uint32_t t) {
- return trgm.trgm < t;
+ uint32_t bucket = hash_trigram(trgm, hdr.hashtable_size);
+ engine->submit_read(fd, sizeof(Trigram) * (hdr.extra_ht_slots + 2), hdr.hash_table_offset_bytes + sizeof(Trigram) * bucket, [this, trgm, bucket, cb{ move(cb) }](string s) {
+ const Trigram *trgmptr = reinterpret_cast<const Trigram *>(s.data());
+ for (unsigned i = 0; i < hdr.extra_ht_slots + 1; ++i) {
+ if (trgmptr[i].trgm == trgm) {
+ cb(trgmptr + i, trgmptr[i + 1].offset - trgmptr[i].offset);
+ return;
+ }
+ }
+
+ // Not found.
+ cb(nullptr, 0);
});
- if (trgmptr == trgm_end || trgmptr->trgm != trgm) {
- return nullptr;
- }
- return trgmptr;
}
-const unsigned char *Corpus::get_compressed_posting_list(const Trigram *trgmptr) const
+void Corpus::get_compressed_filename_block(uint32_t docid, function<void(string)> cb) const
{
- return reinterpret_cast<const unsigned char *>(data + trgmptr->offset);
+ // Read the file offset from this docid and the next one.
+ // This is always allowed, since we have a sentinel block at the end.
+ engine->submit_read(fd, sizeof(uint64_t) * 2, offset_for_block(docid), [this, cb{ move(cb) }](string s) {
+ const uint64_t *ptr = reinterpret_cast<const uint64_t *>(s.data());
+ off_t offset = ptr[0];
+ size_t len = ptr[1] - ptr[0];
+ engine->submit_read(fd, len, offset, cb);
+ });
}
-string_view Corpus::get_compressed_filename_block(uint32_t docid) const
+size_t Corpus::get_num_filename_blocks() const
{
- const char *compressed = (const char *)(data + filename_offsets[docid]);
- size_t compressed_size = filename_offsets[docid + 1] - filename_offsets[docid]; // Allowed we have a sentinel block at the end.
- return {compressed, compressed_size};
+ return hdr.num_docids;
}
-size_t scan_docid(const string &needle, uint32_t docid, const Corpus &corpus, unordered_map<string, bool> *access_rx_cache)
+size_t scan_file_block(const vector<string> &needles, string_view compressed,
+ unordered_map<string, bool> *access_rx_cache, int seq,
+ Serializer *serializer)
{
- string_view compressed = corpus.get_compressed_filename_block(docid);
size_t matched = 0;
+ unsigned long long uncompressed_len = ZSTD_getFrameContentSize(compressed.data(), compressed.size());
+ if (uncompressed_len == ZSTD_CONTENTSIZE_UNKNOWN || uncompressed_len == ZSTD_CONTENTSIZE_ERROR) {
+ fprintf(stderr, "ZSTD_getFrameContentSize() failed\n");
+ exit(1);
+ }
+
string block;
- block.resize(ZSTD_getFrameContentSize(compressed.data(), compressed.size()) + 1);
+ block.resize(uncompressed_len + 1);
- ZSTD_decompress(&block[0], block.size(), compressed.data(), compressed.size());
+ size_t err = ZSTD_decompress(&block[0], block.size(), compressed.data(),
+ compressed.size());
+ if (ZSTD_isError(err)) {
+ fprintf(stderr, "ZSTD_decompress(): %s\n", ZSTD_getErrorName(err));
+ exit(1);
+ }
block[block.size() - 1] = '\0';
+ bool immediate_print = (serializer == nullptr || serializer->ready_to_print(seq));
+ vector<string> delayed;
+
for (const char *filename = block.data();
- filename != block.data() + block.size();
- filename += strlen(filename) + 1) {
- if (strstr(filename, needle.c_str()) == nullptr) {
- continue;
+ filename != block.data() + block.size();
+ filename += strlen(filename) + 1) {
+ bool found = true;
+ for (const string &needle : needles) {
+ if (strstr(filename, needle.c_str()) == nullptr) {
+ found = false;
+ break;
+ }
}
- if (has_access(filename, access_rx_cache)) {
+ if (found && has_access(filename, access_rx_cache)) {
++matched;
- printf("%s\n", filename);
+ if (immediate_print) {
+ if (print_nul) {
+ printf("%s%c", filename, 0);
+ } else {
+ printf("%s\n", filename);
+ }
+ } else {
+ delayed.push_back(filename);
+ }
}
}
+ if (serializer != nullptr) {
+ if (immediate_print) {
+ serializer->release_current();
+ } else {
+ serializer->print_delayed(seq, move(delayed));
+ }
+ }
+ return matched;
+}
+
+size_t scan_docids(const vector<string> &needles, const vector<uint32_t> &docids, const Corpus &corpus, IOUringEngine *engine)
+{
+ Serializer docids_in_order;
+ unordered_map<string, bool> access_rx_cache;
+ size_t matched = 0;
+ for (size_t i = 0; i < docids.size(); ++i) {
+ uint32_t docid = docids[i];
+ corpus.get_compressed_filename_block(docid, [i, &matched, &needles, &access_rx_cache, &docids_in_order](string compressed) {
+ matched += scan_file_block(needles, compressed, &access_rx_cache, i, &docids_in_order);
+ });
+ }
+ engine->finish();
return matched;
}
-void do_search_file(const string &needle, const char *filename)
+// We do this sequentially, as it's faster than scattering
+// a lot of I/O through io_uring and hoping the kernel will
+// coalesce it plus readahead for us.
+void scan_all_docids(const vector<string> &needles, int fd, const Corpus &corpus, IOUringEngine *engine)
+{
+ unordered_map<string, bool> access_rx_cache;
+ uint32_t num_blocks = corpus.get_num_filename_blocks();
+ unique_ptr<uint64_t[]> offsets(new uint64_t[num_blocks + 1]);
+ complete_pread(fd, offsets.get(), (num_blocks + 1) * sizeof(uint64_t), corpus.offset_for_block(0));
+ string compressed;
+ for (uint32_t io_docid = 0; io_docid < num_blocks; io_docid += 32) {
+ uint32_t last_docid = std::min(io_docid + 32, num_blocks);
+ size_t io_len = offsets[last_docid] - offsets[io_docid];
+ if (compressed.size() < io_len) {
+ compressed.resize(io_len);
+ }
+ complete_pread(fd, &compressed[0], io_len, offsets[io_docid]);
+
+ for (uint32_t docid = io_docid; docid < last_docid; ++docid) {
+ size_t relative_offset = offsets[docid] - offsets[io_docid];
+ size_t len = offsets[docid + 1] - offsets[docid];
+ scan_file_block(needles, { &compressed[relative_offset], len }, &access_rx_cache, 0, nullptr);
+ }
+ }
+}
+
+void do_search_file(const vector<string> &needles, const char *filename)
{
int fd = open(filename, O_RDONLY);
if (fd == -1) {
exit(EXIT_FAILURE);
}
- //steady_clock::time_point start = steady_clock::now();
+ steady_clock::time_point start __attribute__((unused)) = steady_clock::now();
if (access("/", R_OK | X_OK)) {
// We can't find anything, no need to bother...
return;
}
- Corpus corpus(fd);
+ IOUringEngine engine;
+ Corpus corpus(fd, &engine);
+ dprintf("Corpus init done after %.1f ms.\n", 1e3 * duration<float>(steady_clock::now() - start).count());
- vector<const Trigram *> trigrams;
- for (size_t i = 0; i < needle.size() - 2; ++i) {
- uint32_t trgm = read_trigram(needle, i);
- const Trigram *trgmptr = corpus.find_trigram(trgm);
- if (trgmptr == nullptr) {
- dprintf("trigram %06x isn't found, we abort the search\n", trgm);
- return;
+ vector<pair<Trigram, size_t>> trigrams;
+ uint64_t shortest_so_far = numeric_limits<uint32_t>::max();
+ for (const string &needle : needles) {
+ if (needle.size() < 3)
+ continue;
+ for (size_t i = 0; i < needle.size() - 2; ++i) {
+ uint32_t trgm = read_trigram(needle, i);
+ corpus.find_trigram(trgm, [trgm, &trigrams, &shortest_so_far](const Trigram *trgmptr, size_t len) {
+ if (trgmptr == nullptr) {
+ dprintf("trigram '%c%c%c' isn't found, we abort the search\n",
+ trgm & 0xff, (trgm >> 8) & 0xff, (trgm >> 16) & 0xff);
+ exit(0);
+ }
+ if (trgmptr->num_docids > shortest_so_far * 100) {
+ dprintf("not loading trigram '%c%c%c' with %u docids, it would be ignored later anyway\n",
+ trgm & 0xff, (trgm >> 8) & 0xff, (trgm >> 16) & 0xff,
+ trgmptr->num_docids);
+ } else {
+ trigrams.emplace_back(*trgmptr, len);
+ shortest_so_far = std::min<uint64_t>(shortest_so_far, trgmptr->num_docids);
+ }
+ });
}
- trigrams.push_back(trgmptr);
+ }
+ engine.finish();
+ dprintf("Hashtable lookups done after %.1f ms.\n", 1e3 * duration<float>(steady_clock::now() - start).count());
+
+ if (trigrams.empty()) {
+ // Too short for trigram matching. Apply brute force.
+ // (We could have searched through all trigrams that matched
+ // the pattern and done a union of them, but that's a lot of
+ // work for fairly unclear gain.)
+ scan_all_docids(needles, fd, corpus, &engine);
+ return;
}
sort(trigrams.begin(), trigrams.end());
{
auto last = unique(trigrams.begin(), trigrams.end());
trigrams.erase(last, trigrams.end());
}
- sort(trigrams.begin(), trigrams.end(), [&](const Trigram *a, const Trigram *b) {
- return a->num_docids < b->num_docids;
- });
+ sort(trigrams.begin(), trigrams.end(),
+ [&](const pair<Trigram, size_t> &a, const pair<Trigram, size_t> &b) {
+ return a.first.num_docids < b.first.num_docids;
+ });
vector<uint32_t> in1, in2, out;
- for (const Trigram *trgmptr : trigrams) {
- //uint32_t trgm = trgmptr->trgm;
- size_t num = trgmptr->num_docids;
- const unsigned char *pldata = corpus.get_compressed_posting_list(trgmptr);
- if (in1.empty()) {
- in1.resize(num + 128);
- p4nd1dec128v32(const_cast<unsigned char *>(pldata), num, &in1[0]);
- in1.resize(num);
- dprintf("trigram '%c%c%c' decoded to %zu entries\n", trgm & 0xff, (trgm >> 8) & 0xff, (trgm >> 16) & 0xff, num);
- } else {
- if (num > in1.size() * 100) {
- dprintf("trigram '%c%c%c' has %zu entries, ignoring the rest (will weed out false positives later)\n",
- trgm & 0xff, (trgm >> 8) & 0xff, (trgm >> 16) & 0xff, num);
- break;
- }
-
- if (in2.size() < num + 128) {
- in2.resize(num + 128);
- }
- p4nd1dec128v32(const_cast<unsigned char *>(pldata), num, &in2[0]);
+ bool done = false;
+ for (auto [trgmptr, len] : trigrams) {
+ if (!in1.empty() && trgmptr.num_docids > in1.size() * 100) {
+ uint32_t trgm __attribute__((unused)) = trgmptr.trgm;
+ dprintf("trigram '%c%c%c' (%zu bytes) has %u entries, ignoring the rest (will "
+ "weed out false positives later)\n",
+ trgm & 0xff, (trgm >> 8) & 0xff, (trgm >> 16) & 0xff,
+ len, trgmptr.num_docids);
+ break;
+ }
- out.clear();
- set_intersection(in1.begin(), in1.end(), in2.begin(), in2.begin() + num, back_inserter(out));
- swap(in1, out);
- dprintf("trigram '%c%c%c' decoded to %zu entries, %zu left\n", trgm & 0xff, (trgm >> 8) & 0xff, (trgm >> 16) & 0xff, num, in1.size());
- if (in1.empty()) {
- dprintf("no matches (intersection list is empty)\n");
+ // Only stay a certain amount ahead, so that we don't spend I/O
+ // on reading the latter, large posting lists. We are unlikely
+ // to need them anyway, even if they should come in first.
+ if (engine.get_waiting_reads() >= 5) {
+ engine.finish();
+ if (done)
break;
- }
}
+ engine.submit_read(fd, len, trgmptr.offset, [trgmptr, len, &done, &in1, &in2, &out](string s) {
+ if (done)
+ return;
+ uint32_t trgm __attribute__((unused)) = trgmptr.trgm;
+ size_t num = trgmptr.num_docids;
+ unsigned char *pldata = reinterpret_cast<unsigned char *>(s.data());
+ if (in1.empty()) {
+ in1.resize(num + 128);
+ decode_pfor_delta1<128>(pldata, num, /*interleaved=*/true, &in1[0]);
+ in1.resize(num);
+ dprintf("trigram '%c%c%c' (%zu bytes) decoded to %zu entries\n", trgm & 0xff,
+ (trgm >> 8) & 0xff, (trgm >> 16) & 0xff, len, num);
+ } else {
+ if (in2.size() < num + 128) {
+ in2.resize(num + 128);
+ }
+ decode_pfor_delta1<128>(pldata, num, /*interleaved=*/true, &in2[0]);
+
+ out.clear();
+ set_intersection(in1.begin(), in1.end(), in2.begin(), in2.begin() + num,
+ back_inserter(out));
+ swap(in1, out);
+ dprintf("trigram '%c%c%c' (%zu bytes) decoded to %zu entries, %zu left\n",
+ trgm & 0xff, (trgm >> 8) & 0xff, (trgm >> 16) & 0xff,
+ len, num, in1.size());
+ if (in1.empty()) {
+ dprintf("no matches (intersection list is empty)\n");
+ done = true;
+ }
+ }
+ });
}
- steady_clock::time_point end = steady_clock::now();
-
- dprintf("Intersection took %.1f ms. Doing final verification and printing:\n",
- 1e3 * duration<float>(end - start).count());
+ engine.finish();
+ if (done) {
+ return;
+ }
+ dprintf("Intersection done after %.1f ms. Doing final verification and printing:\n",
+ 1e3 * duration<float>(steady_clock::now() - start).count());
- unordered_map<string, bool> access_rx_cache;
+ size_t matched __attribute__((unused)) = scan_docids(needles, in1, corpus, &engine);
+ dprintf("Done in %.1f ms, found %zu matches.\n",
+ 1e3 * duration<float>(steady_clock::now() - start).count(), matched);
+}
- int matched = 0;
- for (uint32_t docid : in1) {
- matched += scan_docid(needle, docid, corpus, &access_rx_cache);
- }
- end = steady_clock::now();
- dprintf("Done in %.1f ms, found %d matches.\n",
- 1e3 * duration<float>(end - start).count(), matched);
+void usage()
+{
+ // The help text comes from mlocate.
+ printf("Usage: plocate [OPTION]... PATTERN...\n");
+ printf("\n");
+ printf(" -d, --database DBPATH use DBPATH instead of default database (which is\n");
+ printf(" %s)\n", dbpath);
+ printf(" -h, --help print this help\n");
+ printf(" -0, --null separate entries with NUL on output\n");
}
int main(int argc, char **argv)
{
- //do_search_file(argv[1], "all.trgm");
- do_search_file(argv[1], "/var/lib/mlocate/plocate.db");
+ static const struct option long_options[] = {
+ { "help", no_argument, 0, 'h' },
+ { "database", required_argument, 0, 'd' },
+ { "null", no_argument, 0, '0' },
+ { 0, 0, 0, 0 }
+ };
+
+ for (;;) {
+ int option_index = 0;
+ int c = getopt_long(argc, argv, "d:h0", long_options, &option_index);
+ if (c == -1) {
+ break;
+ }
+ switch (c) {
+ case 'd':
+ dbpath = strdup(optarg);
+ break;
+ case 'h':
+ usage();
+ exit(0);
+ case '0':
+ print_nul = true;
+ break;
+ default:
+ exit(1);
+ }
+ }
+
+ vector<string> needles;
+ for (int i = optind; i < argc; ++i) {
+ needles.push_back(argv[i]);
+ }
+ if (needles.empty()) {
+ fprintf(stderr, "plocate: no pattern to search for specified\n");
+ exit(0);
+ }
+ do_search_file(needles, dbpath);
}
projects / plocate / blobdiff