Adding upstream version 18.2.2.upstream/18.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 73 insertions, 0 deletions

diff --git a/src/rocksdb/file/line_file_reader.cc b/src/rocksdb/file/line_file_reader.cc
new file mode 100644
index 000000000..50c415dc6
--- /dev/null
+++ b/src/rocksdb/file/line_file_reader.cc
@@ -0,0 +1,73 @@
+//  Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#include "file/line_file_reader.h"
+
+#include <cstring>
+
+#include "monitoring/iostats_context_imp.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+IOStatus LineFileReader::Create(const std::shared_ptr<FileSystem>& fs,
+                                const std::string& fname,
+                                const FileOptions& file_opts,
+                                std::unique_ptr<LineFileReader>* reader,
+                                IODebugContext* dbg,
+                                RateLimiter* rate_limiter) {
+  std::unique_ptr<FSSequentialFile> file;
+  IOStatus io_s = fs->NewSequentialFile(fname, file_opts, &file, dbg);
+  if (io_s.ok()) {
+    reader->reset(new LineFileReader(
+        std::move(file), fname, nullptr,
+        std::vector<std::shared_ptr<EventListener>>{}, rate_limiter));
+  }
+  return io_s;
+}
+
+bool LineFileReader::ReadLine(std::string* out,
+                              Env::IOPriority rate_limiter_priority) {
+  assert(out);
+  if (!io_status_.ok()) {
+    // Status should be checked (or permit unchecked) any time we return false.
+    io_status_.MustCheck();
+    return false;
+  }
+  out->clear();
+  for (;;) {
+    // Look for line delimiter
+    const char* found = static_cast<const char*>(
+        std::memchr(buf_begin_, '\n', buf_end_ - buf_begin_));
+    if (found) {
+      size_t len = found - buf_begin_;
+      out->append(buf_begin_, len);
+      buf_begin_ += len + /*delim*/ 1;
+      ++line_number_;
+      return true;
+    }
+    if (at_eof_) {
+      io_status_.MustCheck();
+      return false;
+    }
+    // else flush and reload buffer
+    out->append(buf_begin_, buf_end_ - buf_begin_);
+    Slice result;
+    io_status_ =
+        sfr_.Read(buf_.size(), &result, buf_.data(), rate_limiter_priority);
+    IOSTATS_ADD(bytes_read, result.size());
+    if (!io_status_.ok()) {
+      io_status_.MustCheck();
+      return false;
+    }
+    if (result.size() != buf_.size()) {
+      // The obscure way of indicating EOF
+      at_eof_ = true;
+    }
+    buf_begin_ = result.data();
+    buf_end_ = result.data() + result.size();
+  }
+}
+
+}  // namespace ROCKSDB_NAMESPACE