1 files changed, 197 insertions, 0 deletions
diff --git a/src/rocksdb/db/dbformat.cc b/src/rocksdb/db/dbformat.cc
new file mode 100644
index 000000000..e10af2b85
--- /dev/null
+++ b/src/rocksdb/db/dbformat.cc
@@ -0,0 +1,197 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  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).
+//
+// 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 "db/dbformat.h"
+
+#include <stdio.h>
+#include <cinttypes>
+#include "monitoring/perf_context_imp.h"
+#include "port/port.h"
+#include "util/coding.h"
+#include "util/string_util.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+// kValueTypeForSeek defines the ValueType that should be passed when
+// constructing a ParsedInternalKey object for seeking to a particular
+// sequence number (since we sort sequence numbers in decreasing order
+// and the value type is embedded as the low 8 bits in the sequence
+// number in internal keys, we need to use the highest-numbered
+// ValueType, not the lowest).
+const ValueType kValueTypeForSeek = kTypeBlobIndex;
+const ValueType kValueTypeForSeekForPrev = kTypeDeletion;
+
+uint64_t PackSequenceAndType(uint64_t seq, ValueType t) {
+  assert(seq <= kMaxSequenceNumber);
+  assert(IsExtendedValueType(t));
+  return (seq << 8) | t;
+}
+
+EntryType GetEntryType(ValueType value_type) {
+  switch (value_type) {
+    case kTypeValue:
+      return kEntryPut;
+    case kTypeDeletion:
+      return kEntryDelete;
+    case kTypeSingleDeletion:
+      return kEntrySingleDelete;
+    case kTypeMerge:
+      return kEntryMerge;
+    case kTypeRangeDeletion:
+      return kEntryRangeDeletion;
+    case kTypeBlobIndex:
+      return kEntryBlobIndex;
+    default:
+      return kEntryOther;
+  }
+}
+
+bool ParseFullKey(const Slice& internal_key, FullKey* fkey) {
+  ParsedInternalKey ikey;
+  if (!ParseInternalKey(internal_key, &ikey)) {
+    return false;
+  }
+  fkey->user_key = ikey.user_key;
+  fkey->sequence = ikey.sequence;
+  fkey->type = GetEntryType(ikey.type);
+  return true;
+}
+
+void UnPackSequenceAndType(uint64_t packed, uint64_t* seq, ValueType* t) {
+  *seq = packed >> 8;
+  *t = static_cast<ValueType>(packed & 0xff);
+
+  assert(*seq <= kMaxSequenceNumber);
+  assert(IsExtendedValueType(*t));
+}
+
+void AppendInternalKey(std::string* result, const ParsedInternalKey& key) {
+  result->append(key.user_key.data(), key.user_key.size());
+  PutFixed64(result, PackSequenceAndType(key.sequence, key.type));
+}
+
+void AppendInternalKeyFooter(std::string* result, SequenceNumber s,
+                             ValueType t) {
+  PutFixed64(result, PackSequenceAndType(s, t));
+}
+
+std::string ParsedInternalKey::DebugString(bool hex) const {
+  char buf[50];
+  snprintf(buf, sizeof(buf), "' seq:%" PRIu64 ", type:%d", sequence,
+           static_cast<int>(type));
+  std::string result = "'";
+  result += user_key.ToString(hex);
+  result += buf;
+  return result;
+}
+
+std::string InternalKey::DebugString(bool hex) const {
+  std::string result;
+  ParsedInternalKey parsed;
+  if (ParseInternalKey(rep_, &parsed)) {
+    result = parsed.DebugString(hex);
+  } else {
+    result = "(bad)";
+    result.append(EscapeString(rep_));
+  }
+  return result;
+}
+
+const char* InternalKeyComparator::Name() const { return name_.c_str(); }
+
+int InternalKeyComparator::Compare(const ParsedInternalKey& a,
+                                   const ParsedInternalKey& b) const {
+  // Order by:
+  //    increasing user key (according to user-supplied comparator)
+  //    decreasing sequence number
+  //    decreasing type (though sequence# should be enough to disambiguate)
+  int r = user_comparator_.Compare(a.user_key, b.user_key);
+  if (r == 0) {
+    if (a.sequence > b.sequence) {
+      r = -1;
+    } else if (a.sequence < b.sequence) {
+      r = +1;
+    } else if (a.type > b.type) {
+      r = -1;
+    } else if (a.type < b.type) {
+      r = +1;
+    }
+  }
+  return r;
+}
+
+void InternalKeyComparator::FindShortestSeparator(std::string* start,
+                                                  const Slice& limit) const {
+  // Attempt to shorten the user portion of the key
+  Slice user_start = ExtractUserKey(*start);
+  Slice user_limit = ExtractUserKey(limit);
+  std::string tmp(user_start.data(), user_start.size());
+  user_comparator_.FindShortestSeparator(&tmp, user_limit);
+  if (tmp.size() <= user_start.size() &&
+      user_comparator_.Compare(user_start, tmp) < 0) {
+    // User key has become shorter physically, but larger logically.
+    // Tack on the earliest possible number to the shortened user key.
+    PutFixed64(&tmp,
+               PackSequenceAndType(kMaxSequenceNumber, kValueTypeForSeek));
+    assert(this->Compare(*start, tmp) < 0);
+    assert(this->Compare(tmp, limit) < 0);
+    start->swap(tmp);
+  }
+}
+
+void InternalKeyComparator::FindShortSuccessor(std::string* key) const {
+  Slice user_key = ExtractUserKey(*key);
+  std::string tmp(user_key.data(), user_key.size());
+  user_comparator_.FindShortSuccessor(&tmp);
+  if (tmp.size() <= user_key.size() &&
+      user_comparator_.Compare(user_key, tmp) < 0) {
+    // User key has become shorter physically, but larger logically.
+    // Tack on the earliest possible number to the shortened user key.
+    PutFixed64(&tmp,
+               PackSequenceAndType(kMaxSequenceNumber, kValueTypeForSeek));
+    assert(this->Compare(*key, tmp) < 0);
+    key->swap(tmp);
+  }
+}
+
+LookupKey::LookupKey(const Slice& _user_key, SequenceNumber s,
+                     const Slice* ts) {
+  size_t usize = _user_key.size();
+  size_t ts_sz = (nullptr == ts) ? 0 : ts->size();
+  size_t needed = usize + ts_sz + 13;  // A conservative estimate
+  char* dst;
+  if (needed <= sizeof(space_)) {
+    dst = space_;
+  } else {
+    dst = new char[needed];
+  }
+  start_ = dst;
+  // NOTE: We don't support users keys of more than 2GB :)
+  dst = EncodeVarint32(dst, static_cast<uint32_t>(usize + ts_sz + 8));
+  kstart_ = dst;
+  memcpy(dst, _user_key.data(), usize);
+  dst += usize;
+  if (nullptr != ts) {
+    memcpy(dst, ts->data(), ts_sz);
+    dst += ts_sz;
+  }
+  EncodeFixed64(dst, PackSequenceAndType(s, kValueTypeForSeek));
+  dst += 8;
+  end_ = dst;
+}
+
+void IterKey::EnlargeBuffer(size_t key_size) {
+  // If size is smaller than buffer size, continue using current buffer,
+  // or the static allocated one, as default
+  assert(key_size > buf_size_);
+  // Need to enlarge the buffer.
+  ResetBuffer();
+  buf_ = new char[key_size];
+  buf_size_ = key_size;
+}
+}  // namespace ROCKSDB_NAMESPACE