+#include "access_rx_cache.h"
+#include "complete_pread.h"
#include "db.h"
+#include "dprintf.h"
#include "io_uring_engine.h"
+#include "needle.h"
#include "parse_trigrams.h"
+#include "serializer.h"
#include "turbopfor.h"
#include "unique_sort.h"
#include <algorithm>
#include <assert.h>
+#include <atomic>
#include <chrono>
+#include <condition_variable>
+#include <deque>
#include <fcntl.h>
-#include <fnmatch.h>
#include <functional>
#include <getopt.h>
-#include <iosfwd>
+#include <inttypes.h>
#include <iterator>
#include <limits>
+#include <locale.h>
#include <memory>
-#include <queue>
+#include <mutex>
#include <regex.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <string>
#include <string_view>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <thread>
+#include <tuple>
#include <unistd.h>
#include <unordered_map>
#include <unordered_set>
using namespace std;
using namespace std::chrono;
-#define dprintf(...) \
- do { \
- if (use_debug) { \
- fprintf(stderr, __VA_ARGS__); \
- } \
- } while (false)
-
-#define DEFAULT_DBPATH "/var/lib/mlocate/plocate.db"
-
-const char *dbpath = DEFAULT_DBPATH;
bool ignore_case = false;
bool only_count = false;
bool print_nul = false;
bool use_debug = false;
+bool flush_cache = false;
+bool patterns_are_regex = false;
+bool use_extended_regex = false;
+bool match_basename = false;
+bool check_existence = false;
+bool ignore_visibility = false;
int64_t limit_matches = numeric_limits<int64_t>::max();
+int64_t limit_left = numeric_limits<int64_t>::max();
+bool stdout_is_tty = false;
+bool literal_printing = false;
+static bool in_forked_child = 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) {
- if (limit_matches-- <= 0)
- return;
- 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;
- }
-}
-
-struct Needle {
- enum { STRSTR,
- REGEX, // Not currently used.
- GLOB } type;
- string str; // Filled in no matter what.
- regex_t re; // For REGEX.
-};
-
-bool matches(const Needle &needle, const char *haystack)
-{
- if (needle.type == Needle::STRSTR) {
- return strstr(haystack, needle.str.c_str()) != nullptr;
- } else if (needle.type == Needle::GLOB) {
- int flags = ignore_case ? FNM_CASEFOLD : 0;
- return fnmatch(needle.str.c_str(), haystack, flags) == 0;
- } else {
- assert(needle.type == Needle::REGEX);
- return regexec(&needle.re, haystack, /*nmatch=*/0, /*pmatch=*/nullptr, /*flags=*/0) == 0;
- }
-}
-
-bool has_access(const char *filename,
- unordered_map<string, bool> *access_rx_cache)
-{
- const char *end = strchr(filename + 1, '/');
- while (end != nullptr) {
- string parent_path(filename, end);
- auto it = access_rx_cache->find(parent_path);
- bool ok;
- if (it == access_rx_cache->end()) {
- ok = access(parent_path.c_str(), R_OK | X_OK) == 0;
- access_rx_cache->emplace(move(parent_path), ok);
- } else {
- ok = it->second;
- }
- if (!ok) {
- return false;
- }
- end = strchr(end + 1, '/');
- }
-
- return true;
-}
+steady_clock::time_point start;
+ZSTD_DDict *ddict = nullptr;
class Corpus {
public:
- Corpus(int fd, IOUringEngine *engine);
+ Corpus(int fd, const char *filename_for_errors, IOUringEngine *engine);
~Corpus();
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_view)> cb) const;
{
return hdr.filename_index_offset_bytes + docid * sizeof(uint64_t);
}
+ const Header &get_hdr() const { return hdr; }
public:
const int fd;
Header hdr;
};
-Corpus::Corpus(int fd, IOUringEngine *engine)
+Corpus::Corpus(int fd, const char *filename_for_errors, IOUringEngine *engine)
: fd(fd), engine(engine)
{
- // Enable to test cold-cache behavior (except for access()).
- if (false) {
+ if (flush_cache) {
off_t len = lseek(fd, 0, SEEK_END);
if (len == -1) {
perror("lseek");
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");
+ fprintf(stderr, "%s: database is corrupt or not a plocate database; please rebuild it.\n", filename_for_errors);
exit(1);
}
- if (hdr.version != 0) {
- fprintf(stderr, "plocate.db has version %u, expected 0; please rebuild it.\n", hdr.version);
+ if (hdr.version != 0 && hdr.version != 1) {
+ fprintf(stderr, "%s: has version %u, expected 0 or 1; please rebuild it.\n", filename_for_errors, hdr.version);
exit(1);
}
+ if (hdr.version == 0) {
+ // These will be junk data.
+ hdr.zstd_dictionary_offset_bytes = 0;
+ hdr.zstd_dictionary_length_bytes = 0;
+ }
+ if (hdr.max_version < 2) {
+ // This too. (We ignore the other max_version 2 fields.)
+ hdr.check_visibility = true;
+ }
+ if (ignore_visibility) {
+ hdr.check_visibility = false;
+ }
}
Corpus::~Corpus()
return hdr.num_docids;
}
-uint64_t scan_file_block(const vector<Needle> &needles, string_view compressed,
- unordered_map<string, bool> *access_rx_cache, int seq,
- Serializer *serializer)
+template<class T>
+void stat_if_needed(const char *filename, bool access_ok, IOUringEngine *engine, T cb)
{
- uint64_t matched = 0;
+ if (!access_ok || !check_existence) {
+ // Doesn't have access or doesn't care about existence, so no need to stat.
+ cb(access_ok);
+ } else if (engine == nullptr || !engine->get_supports_stat()) {
+ // Do a synchronous stat.
+ struct stat buf;
+ bool ok = lstat(filename, &buf) == 0;
+ cb(ok);
+ } else {
+ engine->submit_stat(filename, cb);
+ }
+}
+void scan_file_block(const vector<Needle> &needles, string_view compressed,
+ IOUringEngine *engine, AccessRXCache *access_rx_cache, uint64_t seq, ResultReceiver *serializer,
+ atomic<uint64_t> *matched)
+{
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");
string block;
block.resize(uncompressed_len + 1);
- size_t err = ZSTD_decompress(&block[0], block.size(), compressed.data(),
- compressed.size());
+ static thread_local ZSTD_DCtx *ctx = ZSTD_createDCtx(); // Reused across calls.
+ size_t err;
+
+ if (ddict != nullptr) {
+ err = ZSTD_decompress_usingDDict(ctx, &block[0], block.size(), compressed.data(),
+ compressed.size(), ddict);
+ } else {
+ err = ZSTD_decompressDCtx(ctx, &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;
+ auto test_candidate = [&](const char *filename, uint64_t local_seq, uint64_t next_seq) {
+ access_rx_cache->check_access(filename, /*allow_async=*/true, [matched, engine, serializer, local_seq, next_seq, filename{ strdup(filename) }](bool ok) {
+ stat_if_needed(filename, ok, engine, [matched, serializer, local_seq, next_seq, filename](bool ok) {
+ if (ok) {
+ ++*matched;
+ serializer->print(local_seq, next_seq - local_seq, filename);
+ } else {
+ serializer->print(local_seq, next_seq - local_seq, "");
+ }
+ free(filename);
+ });
+ });
+ };
+
+ // We need to know the next sequence number before inserting into Serializer,
+ // so always buffer one candidate.
+ const char *pending_candidate = nullptr;
+ uint64_t local_seq = seq << 32;
for (const char *filename = block.data();
filename != block.data() + block.size();
filename += strlen(filename) + 1) {
+ const char *haystack = filename;
+ if (match_basename) {
+ haystack = strrchr(filename, '/');
+ if (haystack == nullptr) {
+ haystack = filename;
+ } else {
+ ++haystack;
+ }
+ }
+
bool found = true;
for (const Needle &needle : needles) {
- if (!matches(needle, filename)) {
+ if (!matches(needle, haystack)) {
found = false;
break;
}
}
- if (found && has_access(filename, access_rx_cache)) {
- if (limit_matches-- <= 0)
- break;
- ++matched;
- if (only_count)
- continue;
- if (immediate_print) {
- if (print_nul) {
- printf("%s%c", filename, 0);
- } else {
- printf("%s\n", filename);
- }
- } else {
- delayed.push_back(filename);
+ if (found) {
+ if (pending_candidate != nullptr) {
+ test_candidate(pending_candidate, local_seq, local_seq + 1);
+ ++local_seq;
}
+ pending_candidate = filename;
}
}
- if (serializer != nullptr && !only_count) {
- if (immediate_print) {
- serializer->release_current();
- } else {
- serializer->print_delayed(seq, move(delayed));
- }
+ if (pending_candidate == nullptr) {
+ serializer->print(seq << 32, 1ULL << 32, "");
+ } else {
+ test_candidate(pending_candidate, local_seq, (seq + 1) << 32);
}
- return matched;
}
size_t scan_docids(const vector<Needle> &needles, const vector<uint32_t> &docids, const Corpus &corpus, IOUringEngine *engine)
{
Serializer docids_in_order;
- unordered_map<string, bool> access_rx_cache;
- uint64_t matched = 0;
+ AccessRXCache access_rx_cache(engine, corpus.get_hdr().check_visibility);
+ atomic<uint64_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_view compressed) {
- matched += scan_file_block(needles, compressed, &access_rx_cache, i, &docids_in_order);
+ corpus.get_compressed_filename_block(docid, [i, &matched, &needles, &access_rx_cache, engine, &docids_in_order](string_view compressed) {
+ scan_file_block(needles, compressed, engine, &access_rx_cache, i, &docids_in_order, &matched);
});
}
engine->finish();
return matched;
}
+struct WorkerThread {
+ thread t;
+
+ // We use a result queue instead of synchronizing Serializer,
+ // since a lock on it becomes a huge choke point if there are
+ // lots of threads.
+ mutex result_mu;
+ struct Result {
+ uint64_t seq;
+ uint64_t skip;
+ string msg;
+ };
+ vector<Result> results;
+};
+
+class WorkerThreadReceiver : public ResultReceiver {
+public:
+ WorkerThreadReceiver(WorkerThread *wt)
+ : wt(wt) {}
+
+ void print(uint64_t seq, uint64_t skip, const string msg) override
+ {
+ lock_guard<mutex> lock(wt->result_mu);
+ if (msg.empty() && !wt->results.empty() && wt->results.back().seq + wt->results.back().skip == seq) {
+ wt->results.back().skip += skip;
+ } else {
+ wt->results.emplace_back(WorkerThread::Result{ seq, skip, move(msg) });
+ }
+ }
+
+private:
+ WorkerThread *wt;
+};
+
+void deliver_results(WorkerThread *wt, Serializer *serializer)
+{
+ vector<WorkerThread::Result> results;
+ {
+ lock_guard<mutex> lock(wt->result_mu);
+ results = move(wt->results);
+ }
+ for (const WorkerThread::Result &result : results) {
+ serializer->print(result.seq, result.skip, move(result.msg));
+ }
+}
+
// 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.
-uint64_t scan_all_docids(const vector<Needle> &needles, int fd, const Corpus &corpus, IOUringEngine *engine)
+// coalesce it plus readahead for us. Since we assume that
+// we will primarily be CPU-bound, we'll be firing up one
+// worker thread for each spare core (the last one will
+// only be doing I/O). access() is still synchronous.
+uint64_t scan_all_docids(const vector<Needle> &needles, int fd, const Corpus &corpus)
{
- unordered_map<string, bool> access_rx_cache;
+ {
+ const Header &hdr = corpus.get_hdr();
+ if (hdr.zstd_dictionary_length_bytes > 0) {
+ string dictionary;
+ dictionary.resize(hdr.zstd_dictionary_length_bytes);
+ complete_pread(fd, &dictionary[0], hdr.zstd_dictionary_length_bytes, hdr.zstd_dictionary_offset_bytes);
+ ddict = ZSTD_createDDict(dictionary.data(), dictionary.size());
+ }
+ }
+
+ AccessRXCache access_rx_cache(nullptr, corpus.get_hdr().check_visibility);
+ Serializer serializer;
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));
+ atomic<uint64_t> matched{ 0 };
+
+ mutex mu;
+ condition_variable queue_added, queue_removed;
+ deque<tuple<int, int, string>> work_queue; // Under mu.
+ bool done = false; // Under mu.
+
+ unsigned num_threads = max<int>(sysconf(_SC_NPROCESSORS_ONLN) - 1, 1);
+ dprintf("Using %u worker threads for linear scan.\n", num_threads);
+ unique_ptr<WorkerThread[]> threads(new WorkerThread[num_threads]);
+ for (unsigned i = 0; i < num_threads; ++i) {
+ threads[i].t = thread([&threads, &mu, &queue_added, &queue_removed, &work_queue, &done, &offsets, &needles, &access_rx_cache, &matched, i] {
+ // regcomp() takes a lock on the regex, so each thread will need its own.
+ const vector<Needle> *use_needles = &needles;
+ vector<Needle> recompiled_needles;
+ if (i != 0 && patterns_are_regex) {
+ recompiled_needles = needles;
+ for (Needle &needle : recompiled_needles) {
+ needle.re = compile_regex(needle.str);
+ }
+ use_needles = &recompiled_needles;
+ }
+
+ WorkerThreadReceiver receiver(&threads[i]);
+ for (;;) {
+ uint32_t io_docid, last_docid;
+ string compressed;
+
+ {
+ unique_lock lock(mu);
+ queue_added.wait(lock, [&work_queue, &done] { return !work_queue.empty() || done; });
+ if (done && work_queue.empty()) {
+ return;
+ }
+ tie(io_docid, last_docid, compressed) = move(work_queue.front());
+ work_queue.pop_front();
+ queue_removed.notify_all();
+ }
+
+ 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];
+ // IOUringEngine isn't thread-safe, so we do any needed stat()s synchronously (nullptr engine).
+ scan_file_block(*use_needles, { &compressed[relative_offset], len }, /*engine=*/nullptr, &access_rx_cache, docid, &receiver, &matched);
+ }
+ }
+ });
+ }
+
string compressed;
- uint64_t matched = 0;
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];
}
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];
- matched += scan_file_block(needles, { &compressed[relative_offset], len }, &access_rx_cache, 0, nullptr);
- if (limit_matches <= 0)
- return matched;
+ {
+ unique_lock lock(mu);
+ queue_removed.wait(lock, [&work_queue] { return work_queue.size() < 256; }); // Allow ~2MB of data queued up.
+ work_queue.emplace_back(io_docid, last_docid, move(compressed));
+ queue_added.notify_one(); // Avoid the thundering herd.
}
+
+ // Pick up some results, so that we are sure that we won't just overload.
+ // (Seemingly, going through all of these causes slowness with many threads,
+ // but taking only one is OK.)
+ unsigned i = io_docid / 32;
+ deliver_results(&threads[i % num_threads], &serializer);
+ }
+ {
+ lock_guard<mutex> lock(mu);
+ done = true;
+ queue_added.notify_all();
+ }
+ for (unsigned i = 0; i < num_threads; ++i) {
+ threads[i].t.join();
+ deliver_results(&threads[i], &serializer);
}
return matched;
}
return false;
}
-void do_search_file(const vector<Needle> &needles, const char *filename)
+uint64_t do_search_file(const vector<Needle> &needles, const std::string &filename)
{
- int fd = open(filename, O_RDONLY);
+ int fd = open(filename.c_str(), O_RDONLY);
if (fd == -1) {
- perror(filename);
+ perror(filename.c_str());
exit(1);
}
exit(EXIT_FAILURE);
}
- steady_clock::time_point start __attribute__((unused)) = steady_clock::now();
+ start = steady_clock::now();
if (access("/", R_OK | X_OK)) {
// We can't find anything, no need to bother...
- return;
+ return 0;
}
IOUringEngine engine(/*slop_bytes=*/16); // 16 slop bytes as described in turbopfor.h.
- Corpus corpus(fd, &engine);
+ Corpus corpus(fd, filename.c_str(), &engine);
dprintf("Corpus init done after %.1f ms.\n", 1e3 * duration<float>(steady_clock::now() - start).count());
vector<TrigramDisjunction> trigram_groups;
- for (const Needle &needle : needles) {
- if (needle.str.size() < 3)
- continue;
- parse_trigrams(needle.str, ignore_case, &trigram_groups);
+ if (patterns_are_regex) {
+ // We could parse the regex to find trigrams that have to be there
+ // (there are actually known algorithms to deal with disjunctions
+ // and such, too), but for now, we just go brute force.
+ // Using locate with regexes is pretty niche.
+ } else {
+ for (const Needle &needle : needles) {
+ parse_trigrams(needle.str, ignore_case, &trigram_groups);
+ }
}
+
unique_sort(
&trigram_groups,
[](const TrigramDisjunction &a, const TrigramDisjunction &b) { return a.trigram_alternatives < b.trigram_alternatives; },
// (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.)
- uint64_t matched = scan_all_docids(needles, fd, corpus, &engine);
- if (only_count) {
- printf("%zu\n", matched);
+ uint64_t matched = scan_all_docids(needles, fd, corpus);
+ dprintf("Done in %.1f ms, found %" PRId64 " matches.\n",
+ 1e3 * duration<float>(steady_clock::now() - start).count(), matched);
+ return matched;
+ }
+
+ // Sneak in fetching the dictionary, if present. It's not necessarily clear
+ // exactly where it would be cheapest to get it, but it needs to be present
+ // before we can decode any of the posting lists. Most likely, it's
+ // in the same filesystem block as the header anyway, so it should be
+ // present in the cache.
+ {
+ const Header &hdr = corpus.get_hdr();
+ if (hdr.zstd_dictionary_length_bytes > 0) {
+ engine.submit_read(fd, hdr.zstd_dictionary_length_bytes, hdr.zstd_dictionary_offset_bytes, [](string_view s) {
+ ddict = ZSTD_createDDict(s.data(), s.size());
+ dprintf("Dictionary initialized after %.1f ms.\n", 1e3 * duration<float>(steady_clock::now() - start).count());
+ });
}
- return;
}
// Look them all up on disk.
+ bool should_early_exit = false;
for (auto &[trgm, trigram_groups] : trigrams_to_lookup) {
- corpus.find_trigram(trgm, [trgm{ trgm }, trigram_groups{ &trigram_groups }](const Trigram *trgmptr, size_t len) {
+ corpus.find_trigram(trgm, [trgm{ trgm }, trigram_groups{ &trigram_groups }, &should_early_exit](const Trigram *trgmptr, size_t len) {
if (trgmptr == nullptr) {
dprintf("trigram %s isn't found\n", print_trigram(trgm).c_str());
for (TrigramDisjunction *td : *trigram_groups) {
--td->remaining_trigrams_to_read;
+
+ // If we now know this trigram group doesn't match anything at all,
+ // we can do early exit; however, if we're in a forked child,
+ // that would confuse the parent process (since we don't write
+ // our count to the pipe), so we wait until we're back in to the
+ // regular (non-async) context. This is a fairly rare case anyway,
+ // and the gains from dropping the remaining trigram reads are limited.
if (td->remaining_trigrams_to_read == 0 && td->read_trigrams.empty()) {
- dprintf("zero matches in %s, so we are done\n", print_td(*td).c_str());
- if (only_count) {
- printf("0\n");
+ if (in_forked_child) {
+ should_early_exit = true;
+ } else {
+ dprintf("zero matches in %s, so we are done\n", print_td(*td).c_str());
+ if (only_count) {
+ printf("0\n");
+ }
+ exit(1);
}
- exit(0);
}
}
return;
engine.finish();
dprintf("Hashtable lookups done after %.1f ms.\n", 1e3 * duration<float>(steady_clock::now() - start).count());
+ if (should_early_exit) {
+ return 0;
+ }
+
for (TrigramDisjunction &td : trigram_groups) {
// Reset for reads.
td.remaining_trigrams_to_read = td.read_trigrams.size();
if (done)
return;
- uint32_t trgm __attribute__((unused)) = trgmptr.trgm;
+ uint32_t trgm = trgmptr.trgm;
const unsigned char *pldata = reinterpret_cast<const unsigned char *>(s.data());
size_t num = trgmptr.num_docids;
decoded.resize(num);
}
engine.finish();
if (done) {
- return;
+ return 0;
}
dprintf("Intersection done after %.1f ms. Doing final verification and printing:\n",
1e3 * duration<float>(steady_clock::now() - start).count());
uint64_t matched = scan_docids(needles, cur_candidates, corpus, &engine);
- dprintf("Done in %.1f ms, found %zu matches.\n",
+ dprintf("Done in %.1f ms, found %" PRId64 " matches.\n",
1e3 * duration<float>(steady_clock::now() - start).count(), matched);
+ return matched;
+}
- if (only_count) {
- printf("%zu\n", matched);
+// Run do_search_file() in a child process.
+//
+// The reason for this is that we're not robust against malicious input, so we need
+// to drop privileges after opening the file. (Otherwise, we could fall prey to an attack
+// where a user does locate -d badfile.db:/var/lib/plocate/plocate.db, badfile.db contains
+// a buffer overflow that takes over the process, and then uses the elevated privileges
+// to print out otherwise inaccessible paths.) We solve this by forking and treating the
+// child process as untrusted after it has dropped its privileges (which it does before
+// reading any data from the file); it returns a single 64-bit number over a pipe,
+// and that's it. The parent keeps its privileges, and can then fork out new children
+// without fear of being taken over. (The child keeps stdout for outputting results.)
+//
+// The count is returned over the pipe, because it's needed both for --limit and --count.
+uint64_t do_search_file_in_child(const vector<Needle> &needles, const std::string &filename)
+{
+ int pipefd[2];
+ if (pipe(pipefd) == -1) {
+ perror("pipe");
+ exit(EXIT_FAILURE);
+ }
+
+ pid_t child_pid = fork();
+ switch (child_pid) {
+ case 0: {
+ // Child.
+ close(pipefd[0]);
+ in_forked_child = true;
+ uint64_t matched = do_search_file(needles, filename);
+ int ret;
+ do {
+ ret = write(pipefd[1], &matched, sizeof(matched));
+ } while (ret == -1 && errno == EINTR);
+ if (ret != sizeof(matched)) {
+ perror("write");
+ _exit(EXIT_FAILURE);
+ }
+ fflush(stdout);
+ _exit(EXIT_SUCCESS);
}
+ case -1:
+ // Error.
+ perror("fork");
+ exit(EXIT_FAILURE);
+ default:
+ // Parent.
+ close(pipefd[1]);
+ break;
+ }
+
+ // Wait for the child to finish.
+ int wstatus;
+ pid_t err;
+ do {
+ err = waitpid(child_pid, &wstatus, 0);
+ } while (err == -1 && errno == EINTR);
+ if (err == -1) {
+ perror("waitpid");
+ exit(EXIT_FAILURE);
+ }
+ if (WIFEXITED(wstatus)) {
+ if (WEXITSTATUS(wstatus) != 0) {
+ // The child has probably already printed out its error, so just propagate the exit status.
+ exit(WEXITSTATUS(wstatus));
+ }
+ // Success!
+ } else if (!WIFEXITED(wstatus)) {
+ fprintf(stderr, "FATAL: Child died unexpectedly while processing %s\n", filename.c_str());
+ exit(1);
+ }
+
+ // Now get the number of matches from the child.
+ uint64_t matched;
+ int ret;
+ do {
+ ret = read(pipefd[0], &matched, sizeof(matched));
+ } while (ret == -1 && errno == EINTR);
+ if (ret == -1) {
+ perror("read");
+ exit(EXIT_FAILURE);
+ } else if (ret != sizeof(matched)) {
+ fprintf(stderr, "FATAL: Short read through pipe (got %d bytes)\n", ret);
+ exit(EXIT_FAILURE);
+ }
+ close(pipefd[0]);
+ return matched;
}
-string unescape_glob_to_plain_string(const string &needle)
+// Parses a colon-separated list of strings and appends them onto the given vector.
+// Backslash escapes whatever comes after it.
+void parse_dbpaths(const char *ptr, vector<string> *output)
{
- string unescaped;
- for (size_t i = 0; i < needle.size(); i += read_unigram(needle, i).second) {
- uint32_t ch = read_unigram(needle, i).first;
- assert(ch != WILDCARD_UNIGRAM);
- if (ch == PREMATURE_END_UNIGRAM) {
- fprintf(stderr, "Pattern '%s' ended prematurely\n", needle.c_str());
- exit(1);
+ string str;
+ while (*ptr != '\0') {
+ if (*ptr == '\\') {
+ if (ptr[1] == '\0') {
+ fprintf(stderr, "ERROR: Escape character at the end of string\n");
+ exit(EXIT_FAILURE);
+ }
+ // Escape.
+ str.push_back(ptr[1]);
+ ptr += 2;
+ continue;
+ }
+ if (*ptr == ':') {
+ // Separator.
+ output->push_back(move(str));
+ ++ptr;
+ continue;
}
- unescaped.push_back(ch);
+ str.push_back(*ptr++);
}
- return unescaped;
+ output->push_back(move(str));
}
void usage()
printf(
"Usage: plocate [OPTION]... PATTERN...\n"
"\n"
+ " -b, --basename search only the file name portion of path names\n"
" -c, --count print number of matches instead of the matches\n"
" -d, --database DBPATH search for files in DBPATH\n"
- " (default is " DEFAULT_DBPATH ")\n"
+ " (default is " DBFILE ")\n"
" -i, --ignore-case search case-insensitively\n"
" -l, --limit LIMIT stop after LIMIT matches\n"
" -0, --null delimit matches by NUL instead of newline\n"
+ " -N, --literal do not quote filenames, even if printing to a tty\n"
+ " -r, --regexp interpret patterns as basic regexps (slow)\n"
+ " --regex interpret patterns as extended regexps (slow)\n"
+ " -w, --wholename search the entire path name (default; see -b)\n"
" --help print this help\n"
" --version print version information\n");
}
void version()
{
- printf("plocate %s\n", PLOCATE_VERSION);
+ printf("%s %s\n", PACKAGE_NAME, 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");
int main(int argc, char **argv)
{
+ vector<string> dbpaths;
+
+ constexpr int EXTENDED_REGEX = 1000;
+ constexpr int FLUSH_CACHE = 1001;
+ constexpr int IGNORE_VISIBILITY = 1002;
static const struct option long_options[] = {
{ "help", no_argument, 0, 'h' },
{ "count", no_argument, 0, 'c' },
+ { "all", no_argument, 0, 'A' },
+ { "basename", no_argument, 0, 'b' },
{ "database", required_argument, 0, 'd' },
+ { "existing", no_argument, 0, 'e' },
{ "ignore-case", no_argument, 0, 'i' },
{ "limit", required_argument, 0, 'l' },
+ { "literal", no_argument, 0, 'N' },
{ "null", no_argument, 0, '0' },
{ "version", no_argument, 0, 'V' },
+ { "regexp", no_argument, 0, 'r' },
+ { "regex", no_argument, 0, EXTENDED_REGEX },
+ { "wholename", no_argument, 0, 'w' },
{ "debug", no_argument, 0, 'D' }, // Not documented.
+ // Enable to test cold-cache behavior (except for access()). Not documented.
+ { "flush-cache", no_argument, 0, FLUSH_CACHE },
+ // Mostly useful to dump out the entire database, even if the given directories
+ // are gone. Disables sgid due to security. Not documented.
+ { "ignore-visibility", no_argument, 0, IGNORE_VISIBILITY },
{ 0, 0, 0, 0 }
};
setlocale(LC_ALL, "");
for (;;) {
int option_index = 0;
- int c = getopt_long(argc, argv, "cd:hil:n:0VD", long_options, &option_index);
+ int c = getopt_long(argc, argv, "Abcd:ehil:n:N0rwVD", long_options, &option_index);
if (c == -1) {
break;
}
switch (c) {
+ case 'A':
+ // Ignored.
+ break;
+ case 'b':
+ match_basename = true;
+ break;
case 'c':
only_count = true;
break;
case 'd':
- dbpath = strdup(optarg);
+ parse_dbpaths(optarg, &dbpaths);
+ break;
+ case 'e':
+ check_existence = true;
break;
case 'h':
usage();
break;
case 'l':
case 'n':
- limit_matches = atoll(optarg);
+ limit_matches = limit_left = atoll(optarg);
+ if (limit_matches <= 0) {
+ fprintf(stderr, "Error: limit must be a strictly positive number.\n");
+ exit(1);
+ }
+ break;
+ case 'N':
+ literal_printing = true;
break;
case '0':
print_nul = true;
break;
+ case 'r':
+ patterns_are_regex = true;
+ break;
+ case EXTENDED_REGEX:
+ patterns_are_regex = true;
+ use_extended_regex = true;
+ break;
+ case 'w':
+ match_basename = false; // No-op unless -b is given first.
+ break;
case 'D':
use_debug = true;
break;
+ case FLUSH_CACHE:
+ flush_cache = true;
+ break;
case 'V':
version();
break;
+ case IGNORE_VISIBILITY:
+ ignore_visibility = true;
+ break;
default:
exit(1);
}
}
- if (use_debug) {
+ if (use_debug || flush_cache || ignore_visibility) {
// Debug information would leak information about which files exist,
// so drop setgid before we open the file; one would either need to run
- // as root, or use a locally-built file.
+ // as root, or use a locally-built file. Doing the same thing for
+ // flush_cache is mostly paranoia, in an attempt to prevent random users
+ // from making plocate slow for everyone else.
+ // --ignore-visibility is obvious; if we allowed to keep sgid with
+ // that flag on, it would subvert the entire security model.
if (setgid(getgid()) != 0) {
perror("setgid");
exit(EXIT_FAILURE);
}
}
+ if (!print_nul) {
+ stdout_is_tty = isatty(1);
+ }
+
vector<Needle> needles;
for (int i = optind; i < argc; ++i) {
Needle needle;
}
}
- if (any_wildcard) {
+ if (patterns_are_regex) {
+ needle.type = Needle::REGEX;
+ needle.re = compile_regex(needle.str);
+ } else if (any_wildcard) {
needle.type = Needle::GLOB;
} else if (ignore_case) {
// strcasestr() doesn't handle locales correctly (even though LSB
}
if (needles.empty()) {
fprintf(stderr, "plocate: no pattern to search for specified\n");
- exit(0);
+ exit(1);
+ }
+
+ if (dbpaths.empty()) {
+ // No -d given, so use our default. Note that this happens
+ // even if LOCATE_PATH exists, to match mlocate behavior.
+ dbpaths.push_back(DBFILE);
}
- do_search_file(needles, dbpath);
+
+ const char *locate_path = getenv("LOCATE_PATH");
+ if (locate_path != nullptr) {
+ parse_dbpaths(locate_path, &dbpaths);
+ }
+
+ uint64_t matched = 0;
+ for (size_t i = 0; i < dbpaths.size(); ++i) {
+ uint64_t this_matched;
+ if (i != dbpaths.size() - 1) {
+ this_matched = do_search_file_in_child(needles, dbpaths[i]);
+ } else {
+ this_matched = do_search_file(needles, dbpaths[i]);
+ }
+ matched += this_matched;
+ limit_left -= this_matched;
+ }
+ if (only_count) {
+ printf("%" PRId64 "\n", matched);
+ }
+
+ return matched == 0;
}
projects / plocate / blobdiff