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- /*
- Copyright (c) 2020 Sogou, Inc.
- Licensed under the Apache License, Version 2.0 (the "License");
- you may not use this file except in compliance with the License.
- You may obtain a copy of the License at
- http://www.apache.org/licenses/LICENSE-2.0
- Unless required by applicable law or agreed to in writing, software
- distributed under the License is distributed on an "AS IS" BASIS,
- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- See the License for the specific language governing permissions and
- limitations under the License.
- */
- #ifndef __RPC_BUFFER_H__
- #define __RPC_BUFFER_H__
- #ifdef _WIN32
- #include <workflow/PlatformSocket.h>
- #else
- #include <sys/uio.h>
- #endif
- #include <stddef.h>
- #include <string.h>
- #include <list>
- namespace srpc
- {
- static constexpr int BUFFER_PIECE_MIN_SIZE = 2 * 1024;
- static constexpr int BUFFER_PIECE_MAX_SIZE = 256 * 1024;
- static constexpr int BUFFER_MODE_COPY = 0;
- static constexpr int BUFFER_MODE_NOCOPY = 1;
- static constexpr int BUFFER_MODE_GIFT_NEW = 2;
- static constexpr int BUFFER_MODE_GIFT_MALLOC = 3;
- static constexpr bool BUFFER_FETCH_MOVE = true;
- static constexpr bool BUFFER_FETCH_STAY = false;
- /**
- * @brief Buffer Class
- * @details
- * - Thread Safety : NO
- * - All buffer should allocated by new char[...] or malloc
- * - Gather buffer piece by piece
- * - Get buffer one by one
- */
- class RPCBuffer
- {
- public:
- /**
- * @brief Free all buffer and rewind every state to initialize.
- * @note NEVER fail
- */
- void clear();
- /**
- * @brief Get all size of buffer
- */
- size_t size() const { return size_; }
- /**
- * @brief Cut current buffer at absolutely offset. Current buffer keeps
- * the first part and gives the second part to the out buffer.
- * @param[in] offset where to cut
- * @param[in] out points to out buffer
- * @return actual give how many bytes to out
- * @note this will cause current buffer rewind()
- */
- size_t cut(size_t offset, RPCBuffer *out);
- public:
- /**
- * @brief For write. Add one buffer allocated by RPCBuffer
- * @param[in,out] buf a pointer to a buffer
- * @param[in,out] size points to the expect size of buffer, return actual size
- * @return false if OOM, or your will get a buffer actual size <=expect-size
- * @note Ownership of this buffer remains with the stream
- */
- bool acquire(void **buf, size_t *size);
- /**
- * @brief For write. Add one buffer allocated by RPCBuffer
- * @param[in,out] buf a pointer to a buffer
- * @return 0 if OOM, or the actual size of the buffer
- * @note Ownership of this buffer remains with the stream
- */
- size_t acquire(void **buf);
- /**
- * @brief For write. Add one buffer
- * @param[in] buf upstream name
- * @param[in] buflen consistent-hash functional
- * @param[in] mode BUFFER_MODE_XXX
- * @return false if OOM
- * @note BUFFER_MODE_NOCOPY mean in deconstructor ignore this buffer
- * @note BUFFER_MODE_COPY mean memcpy this buffer right here at once
- * @note BUFFER_MODE_GIFT_NEW mean in deconstructor delete this buffer
- * @note BUFFER_MODE_GIFT_MALLOC mean in deconstructor free this buffer
- */
- bool append(void *buf, size_t buflen, int mode);
- bool append(const void *buf, size_t buflen, int mode);
- /**
- * @brief For write. Backs up a number of bytes of last buffer
- * @param[in] count how many bytes back up
- * @return the actual bytes backup
- * @note It is affect the buffer with both acquire and append
- * @note count should be less than or equal to the size of the last buffer
- */
- size_t backup(size_t count);
- /**
- * @brief For write. Add one buffer use memcpy
- * @param[in] buf buffer
- * @param[in] buflen buffer size
- * @return false if OOM
- */
- bool write(const void *buf, size_t buflen);
- public:
- /**
- * @brief For workflow message encode.
- * @param[in] iov iov vector
- * @param[in] count iov vector count
- * @return use how many iov
- * @retval -1 when count <=0, and set errno EINVAL
- */
- int encode(struct iovec *iov, int count);
- /**
- * @brief merge all buffer into one piece
- * @param[out] iov pointer and length of result
- * @return suceess or OOM
- * @retval 0 success
- * @retval -1 OOM
- */
- int merge_all(struct iovec& iov);
- public:
- /**
- * @brief For read. Reset buffer position to head
- * @note NEVER fail
- */
- void rewind();
- /**
- * @brief For read. Get one buffer, NO move offset
- * @param[in,out] buf a pointer to a buffer
- * @return 0 if no more data to read, or the forward size available
- */
- size_t peek(const void **buf);
- /**
- * @brief For read. Get one buffer by except size, move offset
- * @param[in,out] buf a pointer to a buffer
- * @param[in,out] size except buffer size, and return actual size
- * @return false if OOM, or your will get a buffer actual size <=expect-size
- */
- bool fetch(const void **buf, size_t *size);
- /**
- * @brief For read. Get one buffer, move offset
- * @param[in,out] buf a pointer to a buffer
- * @return 0 if no more data to read, or the forward size available
- */
- size_t fetch(const void **buf);
- /**
- * @brief For read. Fill one buffer with memcpy, move offset
- * @param[in] buf buffer wait to fill
- * @param[in] buflen except buffer size
- * @return true if fill buffer exactly bytes, false if no more data to read
- */
- bool read(void *buf, size_t buflen);
- /**
- * @brief For read. move offset, positive mean skip, negative mean backward
- * @param[in] offset except move offset
- * @return actual move offset
- * @note If offset=0, do nothing at all
- */
- long seek(long offset);
- public:
- void set_piece_min_size(size_t size) { piece_min_size_ = size; }
- void set_piece_max_size(size_t size) { piece_max_size_ = size; }
- RPCBuffer() = default;
- ~RPCBuffer();
- RPCBuffer(const RPCBuffer&) = delete;
- RPCBuffer(RPCBuffer&&) = delete;
- RPCBuffer& operator=(const RPCBuffer&) = delete;
- RPCBuffer& operator=(RPCBuffer&&) = delete;
- private:
- struct buffer_t
- {
- void *buf;
- size_t buflen;
- bool is_nocopy;
- bool is_new;
- };
- void clear_list_buffer();
- size_t internal_fetch(const void **buf, bool move_or_stay);
- long read_skip(long offset);
- long read_back(long offset);
- std::list<buffer_t> buffer_list_;
- std::pair<std::list<buffer_t>::iterator, size_t> cur_;
- size_t size_ = 0;
- size_t piece_min_size_ = BUFFER_PIECE_MIN_SIZE;
- size_t piece_max_size_ = BUFFER_PIECE_MAX_SIZE;
- bool init_read_over_ = false;
- size_t last_piece_left_ = 0;
- };
- } // namespace srpc
- #endif
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