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Diffstat (limited to 'src/leveldb/port/port_example.h')
-rw-r--r-- | src/leveldb/port/port_example.h | 135 |
1 files changed, 0 insertions, 135 deletions
diff --git a/src/leveldb/port/port_example.h b/src/leveldb/port/port_example.h deleted file mode 100644 index ab9e489b3..000000000 --- a/src/leveldb/port/port_example.h +++ /dev/null @@ -1,135 +0,0 @@ -// 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. -// -// This file contains the specification, but not the implementations, -// of the types/operations/etc. that should be defined by a platform -// specific port_<platform>.h file. Use this file as a reference for -// how to port this package to a new platform. - -#ifndef STORAGE_LEVELDB_PORT_PORT_EXAMPLE_H_ -#define STORAGE_LEVELDB_PORT_PORT_EXAMPLE_H_ - -namespace leveldb { -namespace port { - -// TODO(jorlow): Many of these belong more in the environment class rather than -// here. We should try moving them and see if it affects perf. - -// The following boolean constant must be true on a little-endian machine -// and false otherwise. -static const bool kLittleEndian = true /* or some other expression */; - -// ------------------ Threading ------------------- - -// A Mutex represents an exclusive lock. -class Mutex { - public: - Mutex(); - ~Mutex(); - - // Lock the mutex. Waits until other lockers have exited. - // Will deadlock if the mutex is already locked by this thread. - void Lock(); - - // Unlock the mutex. - // REQUIRES: This mutex was locked by this thread. - void Unlock(); - - // Optionally crash if this thread does not hold this mutex. - // The implementation must be fast, especially if NDEBUG is - // defined. The implementation is allowed to skip all checks. - void AssertHeld(); -}; - -class CondVar { - public: - explicit CondVar(Mutex* mu); - ~CondVar(); - - // Atomically release *mu and block on this condition variable until - // either a call to SignalAll(), or a call to Signal() that picks - // this thread to wakeup. - // REQUIRES: this thread holds *mu - void Wait(); - - // If there are some threads waiting, wake up at least one of them. - void Signal(); - - // Wake up all waiting threads. - void SignallAll(); -}; - -// Thread-safe initialization. -// Used as follows: -// static port::OnceType init_control = LEVELDB_ONCE_INIT; -// static void Initializer() { ... do something ...; } -// ... -// port::InitOnce(&init_control, &Initializer); -typedef intptr_t OnceType; -#define LEVELDB_ONCE_INIT 0 -extern void InitOnce(port::OnceType*, void (*initializer)()); - -// A type that holds a pointer that can be read or written atomically -// (i.e., without word-tearing.) -class AtomicPointer { - private: - intptr_t rep_; - public: - // Initialize to arbitrary value - AtomicPointer(); - - // Initialize to hold v - explicit AtomicPointer(void* v) : rep_(v) { } - - // Read and return the stored pointer with the guarantee that no - // later memory access (read or write) by this thread can be - // reordered ahead of this read. - void* Acquire_Load() const; - - // Set v as the stored pointer with the guarantee that no earlier - // memory access (read or write) by this thread can be reordered - // after this store. - void Release_Store(void* v); - - // Read the stored pointer with no ordering guarantees. - void* NoBarrier_Load() const; - - // Set va as the stored pointer with no ordering guarantees. - void NoBarrier_Store(void* v); -}; - -// ------------------ Compression ------------------- - -// Store the snappy compression of "input[0,input_length-1]" in *output. -// Returns false if snappy is not supported by this port. -extern bool Snappy_Compress(const char* input, size_t input_length, - std::string* output); - -// If input[0,input_length-1] looks like a valid snappy compressed -// buffer, store the size of the uncompressed data in *result and -// return true. Else return false. -extern bool Snappy_GetUncompressedLength(const char* input, size_t length, - size_t* result); - -// Attempt to snappy uncompress input[0,input_length-1] into *output. -// Returns true if successful, false if the input is invalid lightweight -// compressed data. -// -// REQUIRES: at least the first "n" bytes of output[] must be writable -// where "n" is the result of a successful call to -// Snappy_GetUncompressedLength. -extern bool Snappy_Uncompress(const char* input_data, size_t input_length, - char* output); - -// ------------------ Miscellaneous ------------------- - -// If heap profiling is not supported, returns false. -// Else repeatedly calls (*func)(arg, data, n) and then returns true. -// The concatenation of all "data[0,n-1]" fragments is the heap profile. -extern bool GetHeapProfile(void (*func)(void*, const char*, int), void* arg); - -} // namespace port -} // namespace leveldb - -#endif // STORAGE_LEVELDB_PORT_PORT_EXAMPLE_H_ |