aboutsummaryrefslogtreecommitdiff
path: root/src/leveldb/util/env_boost.cc
blob: 0190f9fb776c5ef274ba0208601d5f50992f8307 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.

#include <deque>

#ifdef LEVELDB_PLATFORM_WINDOWS
#include <windows.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <time.h>
#include <io.h>
#else
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/param.h>
#include <time.h>
#include <unistd.h>
#endif
#if defined(LEVELDB_PLATFORM_ANDROID)
#include <sys/stat.h>
#endif
#include "leveldb/env.h"
#include "leveldb/slice.h"

#ifdef LEVELDB_PLATFORM_WINDOWS
#include "util/win_logger.h"
#else
#include "util/posix_logger.h"
#endif
#include "port/port.h"
#include "util/logging.h"

#ifdef __linux
#include <sys/sysinfo.h>
#include <linux/unistd.h>
#endif

#include <fstream>

// Boost includes - see WINDOWS file to see which modules to install
#include <boost/date_time/gregorian/gregorian.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>
#include <boost/filesystem/convenience.hpp>
#include <boost/thread/once.hpp>
#include <boost/thread/thread.hpp>
#include <boost/bind.hpp>
#include <boost/scoped_ptr.hpp>
#include <boost/interprocess/sync/file_lock.hpp>
#include <boost/thread/condition_variable.hpp>

namespace leveldb {
namespace {

// returns the ID of the current process
static boost::uint32_t current_process_id(void) {
#ifdef _WIN32
  return static_cast<boost::uint32_t>(::GetCurrentProcessId());
#else
  return static_cast<boost::uint32_t>(::getpid());
#endif
}

// returns the ID of the current thread
static boost::uint32_t current_thread_id(void) {
#ifdef _WIN32
  return static_cast<boost::uint32_t>(::GetCurrentThreadId());
#else
#ifdef __linux
  return static_cast<boost::uint32_t>(::syscall(__NR_gettid));
#else
  // just return the pid
  return current_process_id();
#endif
#endif
}

static char global_read_only_buf[0x8000];

class PosixSequentialFile: public SequentialFile {
 private:
  std::string filename_;
  FILE* file_;

 public:
  PosixSequentialFile(const std::string& fname, FILE* f)
    : filename_(fname), file_(f) { }
  virtual ~PosixSequentialFile() { fclose(file_); }

  virtual Status Read(size_t n, Slice* result, char* scratch) {
  Status s;
#if defined(BSD) || defined(__MINGW32__)
  // fread_unlocked doesn't exist on FreeBSD or MingW
  size_t r = fread(scratch, 1, n, file_);
#else
  size_t r = fread_unlocked(scratch, 1, n, file_);
#endif
  *result = Slice(scratch, r);
  if (r < n) {
    if (feof(file_)) {
    // We leave status as ok if we hit the end of the file
    } else {
    // A partial read with an error: return a non-ok status
    s = Status::IOError(filename_, strerror(errno));
    }
  }
  return s;
  }

  virtual Status Skip(uint64_t n) {
  if (fseek(file_, n, SEEK_CUR)) {
    return Status::IOError(filename_, strerror(errno));
  }
  return Status::OK();
  }
};

class PosixRandomAccessFile: public RandomAccessFile {
 private:
  std::string filename_;
  int fd_;
  mutable boost::mutex mu_;

 public:
  PosixRandomAccessFile(const std::string& fname, int fd)
    : filename_(fname), fd_(fd) { }
  virtual ~PosixRandomAccessFile() { close(fd_); }

  virtual Status Read(uint64_t offset, size_t n, Slice* result,
            char* scratch) const {
    Status s;
#ifdef LEVELDB_PLATFORM_WINDOWS
    // no pread on Windows so we emulate it with a mutex
    boost::unique_lock<boost::mutex> lock(mu_);

    if (::_lseeki64(fd_, offset, SEEK_SET) == -1L) {
      return Status::IOError(filename_, strerror(errno));
    }

    int r = ::_read(fd_, scratch, n);
    *result = Slice(scratch, (r < 0) ? 0 : r);
    lock.unlock();
#else
    ssize_t r = pread(fd_, scratch, n, static_cast<off_t>(offset));
    *result = Slice(scratch, (r < 0) ? 0 : r);
#endif
    if (r < 0) {
      // An error: return a non-ok status
      s = Status::IOError(filename_, strerror(errno));
    }
    return s;
  }
};

// We preallocate up to an extra megabyte and use memcpy to append new
// data to the file.  This is safe since we either properly close the
// file before reading from it, or for log files, the reading code
// knows enough to skip zero suffixes.

class BoostFile : public WritableFile {

public:
  explicit BoostFile(std::string path) : path_(path), written_(0) {
    Open();
  }

  virtual ~BoostFile() {
    Close();
  }

private:
  void Open() {
    // we truncate the file as implemented in env_posix
     file_.open(path_.generic_string().c_str(), 
         std::ios_base::trunc | std::ios_base::out | std::ios_base::binary);
     written_ = 0;
  }

public:
  virtual Status Append(const Slice& data) {
    Status result;
    file_.write(data.data(), data.size());
    if (!file_.good()) {
      result = Status::IOError(
          path_.generic_string() + " Append", "cannot write");
    }
    return result;
  }

  virtual Status Close() {
    Status result;

    try {
      if (file_.is_open()) {
        Sync();
        file_.close();
      }
    } catch (const std::exception & e) {
      result = Status::IOError(path_.generic_string() + " close", e.what());
    }

    return result;
  }

  virtual Status Flush() {
    file_.flush();
    return Status::OK();
  }

  virtual Status Sync() {
    Status result;
    try {
      Flush();
    } catch (const std::exception & e) {
      result = Status::IOError(path_.string() + " sync", e.what());
    }

    return result;
  }

private:
  boost::filesystem::path path_;
  boost::uint64_t written_;
  std::ofstream file_;
};



class BoostFileLock : public FileLock {
 public:
  boost::interprocess::file_lock fl_;
};

class PosixEnv : public Env {
 public:
  PosixEnv();
  virtual ~PosixEnv() {
    fprintf(stderr, "Destroying Env::Default()\n");
    exit(1);
  }

  virtual Status NewSequentialFile(const std::string& fname,
                   SequentialFile** result) {
    FILE* f = fopen(fname.c_str(), "rb");
    if (f == NULL) {
      *result = NULL;
      return Status::IOError(fname, strerror(errno));
    } else {
      *result = new PosixSequentialFile(fname, f);
      return Status::OK();
    }
  }

  virtual Status NewRandomAccessFile(const std::string& fname,
                   RandomAccessFile** result) {
#ifdef LEVELDB_PLATFORM_WINDOWS
    int fd = _open(fname.c_str(), _O_RDONLY | _O_RANDOM | _O_BINARY);
#else
    int fd = open(fname.c_str(), O_RDONLY);
#endif
    if (fd < 0) {
      *result = NULL;
      return Status::IOError(fname, strerror(errno));
    }
    *result = new PosixRandomAccessFile(fname, fd);
    return Status::OK();
  }

  virtual Status NewWritableFile(const std::string& fname,
                 WritableFile** result) {
    Status s;
    try {
      // will create a new empty file to write to
      *result = new BoostFile(fname);
    }
    catch (const std::exception & e) {
      s = Status::IOError(fname, e.what());
    }

    return s;
  }

  virtual bool FileExists(const std::string& fname) {
    return boost::filesystem::exists(fname);
  }

  virtual Status GetChildren(const std::string& dir,
               std::vector<std::string>* result) {
    result->clear();

    boost::system::error_code ec;
    boost::filesystem::directory_iterator current(dir, ec);
    if (ec != 0) {
      return Status::IOError(dir, ec.message());
    }

    boost::filesystem::directory_iterator end;

    for(; current != end; ++current) {
      result->push_back(current->path().filename().generic_string());
    }

    return Status::OK();
  }

  virtual Status DeleteFile(const std::string& fname) {
    boost::system::error_code ec;

    boost::filesystem::remove(fname, ec);

    Status result;

    if (ec != 0) {
      result = Status::IOError(fname, ec.message());
    }

    return result;
  }

  virtual Status CreateDir(const std::string& name) {
      Status result;

      if (boost::filesystem::exists(name) &&
          boost::filesystem::is_directory(name)) {
        return result;
      }

      boost::system::error_code ec;

      if (!boost::filesystem::create_directories(name, ec)) {
        result = Status::IOError(name, ec.message());
      }

      return result;
    };

    virtual Status DeleteDir(const std::string& name) {
    Status result;

    boost::system::error_code ec;
    if (!boost::filesystem::remove_all(name, ec)) {
      result = Status::IOError(name, ec.message());
    }

    return result;
  };

  virtual Status GetFileSize(const std::string& fname, uint64_t* size) {
    boost::system::error_code ec;

    Status result;

    *size = static_cast<uint64_t>(boost::filesystem::file_size(fname, ec));
    if (ec != 0) {
      *size = 0;
       result = Status::IOError(fname, ec.message());
    }

    return result;
  }

  virtual Status RenameFile(const std::string& src, const std::string& target) {
    boost::system::error_code ec;

    boost::filesystem::rename(src, target, ec);

    Status result;

    if (ec != 0) {
      result = Status::IOError(src, ec.message());
    }

    return result;
  }

  virtual Status LockFile(const std::string& fname, FileLock** lock) {
    *lock = NULL;

    Status result;

    try {
      if (!boost::filesystem::exists(fname)) {
        std::ofstream of(fname.c_str(), std::ios_base::trunc | std::ios_base::out);
      }

      assert(boost::filesystem::exists(fname));

      boost::interprocess::file_lock fl(fname.c_str());
      BoostFileLock * my_lock = new BoostFileLock();
      my_lock->fl_ = std::move(fl);
      if (!my_lock->fl_.try_lock()) {
          return Status::IOError("database already in use: could not acquire exclusive lock");
      }
      *lock = my_lock;
    } catch (const std::exception & e) {
      result = Status::IOError("lock " + fname, e.what());
    }

    return result;
  }

  virtual Status UnlockFile(FileLock* lock) {

    Status result;

    try {
      BoostFileLock * my_lock = static_cast<BoostFileLock *>(lock);
      my_lock->fl_.unlock();
      delete my_lock;
    } catch (const std::exception & e) {
      result = Status::IOError("unlock", e.what());
    }

    return result;
  }

  virtual void Schedule(void (*function)(void*), void* arg);

  virtual void StartThread(void (*function)(void* arg), void* arg);

  virtual Status GetTestDirectory(std::string* result) {
    boost::system::error_code ec;
    boost::filesystem::path temp_dir = 
        boost::filesystem::temp_directory_path(ec);
    if (ec != 0) {
      temp_dir = "tmp";
    }

    temp_dir /= "leveldb_tests";
    temp_dir /= boost::lexical_cast<std::string>(current_process_id());

    // Directory may already exist
    CreateDir(temp_dir.generic_string());

    *result = temp_dir.generic_string();

    return Status::OK();
  }

#ifndef LEVELDB_PLATFORM_WINDOWS
  static uint64_t gettid() {
    pthread_t tid = pthread_self();
    uint64_t thread_id = 0;
    memcpy(&thread_id, &tid, std::min(sizeof(thread_id), sizeof(tid)));
    return thread_id;
  }
#endif

  virtual Status NewLogger(const std::string& fname, Logger** result) {
  FILE* f = fopen(fname.c_str(), "wt");
  if (f == NULL) {
    *result = NULL;
    return Status::IOError(fname, strerror(errno));
  } else {
#ifdef LEVELDB_PLATFORM_WINDOWS
    *result = new WinLogger(f);
#else
    *result = new PosixLogger(f, &PosixEnv::gettid);
#endif
    return Status::OK();
  }
  }

  virtual uint64_t NowMicros() {
    return static_cast<uint64_t>(
        boost::posix_time::microsec_clock::universal_time()
        .time_of_day().total_microseconds());
  }

  virtual void SleepForMicroseconds(int micros) {
  boost::this_thread::sleep(boost::posix_time::microseconds(micros));
  }

 private:
  void PthreadCall(const char* label, int result) {
  if (result != 0) {
    fprintf(stderr, "pthread %s: %s\n", label, strerror(result));
    exit(1);
  }
  }

  // BGThread() is the body of the background thread
  void BGThread();

  static void* BGThreadWrapper(void* arg) {
    reinterpret_cast<PosixEnv*>(arg)->BGThread();
    return NULL;
  }

  boost::mutex mu_;
  boost::condition_variable bgsignal_;
  boost::scoped_ptr<boost::thread> bgthread_;

  // Entry per Schedule() call
  struct BGItem { void* arg; void (*function)(void*); };
  typedef std::deque<BGItem> BGQueue;
  BGQueue queue_;
};

PosixEnv::PosixEnv() { }

void PosixEnv::Schedule(void (*function)(void*), void* arg) {
  boost::unique_lock<boost::mutex> lock(mu_);

  // Start background thread if necessary
  if (!bgthread_) {
     bgthread_.reset(
         new boost::thread(boost::bind(&PosixEnv::BGThreadWrapper, this)));
  }

  // Add to priority queue
  queue_.push_back(BGItem());
  queue_.back().function = function;
  queue_.back().arg = arg;

  lock.unlock();

  bgsignal_.notify_one();

}

void PosixEnv::BGThread() {
  while (true) {
  // Wait until there is an item that is ready to run
  boost::unique_lock<boost::mutex> lock(mu_);

  while (queue_.empty()) {
    bgsignal_.wait(lock);
  }

  void (*function)(void*) = queue_.front().function;
  void* arg = queue_.front().arg;
  queue_.pop_front();

  lock.unlock();
  (*function)(arg);
  }
}

namespace {
struct StartThreadState {
  void (*user_function)(void*);
  void* arg;
};
}

static void* StartThreadWrapper(void* arg) {
  StartThreadState* state = reinterpret_cast<StartThreadState*>(arg);
  state->user_function(state->arg);
  delete state;
  return NULL;
}

void PosixEnv::StartThread(void (*function)(void* arg), void* arg) {
  StartThreadState* state = new StartThreadState;
  state->user_function = function;
  state->arg = arg;

  boost::thread t(boost::bind(&StartThreadWrapper, state));
}

}

static boost::once_flag once = BOOST_ONCE_INIT;
static Env* default_env;
static void InitDefaultEnv() { 
  ::memset(global_read_only_buf, 0, sizeof(global_read_only_buf));
  default_env = new PosixEnv;
}

Env* Env::Default() {
  boost::call_once(once, InitDefaultEnv);

  return default_env;
}

}