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Diffstat (limited to 'deps/node/deps/brotli/c/enc/ringbuffer.h')
| -rw-r--r-- | deps/node/deps/brotli/c/enc/ringbuffer.h | 164 |
1 files changed, 0 insertions, 164 deletions
diff --git a/deps/node/deps/brotli/c/enc/ringbuffer.h b/deps/node/deps/brotli/c/enc/ringbuffer.h deleted file mode 100644 index 86079a89..00000000 --- a/deps/node/deps/brotli/c/enc/ringbuffer.h +++ /dev/null @@ -1,164 +0,0 @@ -/* Copyright 2013 Google Inc. All Rights Reserved. - - Distributed under MIT license. - See file LICENSE for detail or copy at https://opensource.org/licenses/MIT -*/ - -/* Sliding window over the input data. */ - -#ifndef BROTLI_ENC_RINGBUFFER_H_ -#define BROTLI_ENC_RINGBUFFER_H_ - -#include <string.h> /* memcpy */ - -#include "../common/platform.h" -#include <brotli/types.h> -#include "./memory.h" -#include "./quality.h" - -#if defined(__cplusplus) || defined(c_plusplus) -extern "C" { -#endif - -/* A RingBuffer(window_bits, tail_bits) contains `1 << window_bits' bytes of - data in a circular manner: writing a byte writes it to: - `position() % (1 << window_bits)'. - For convenience, the RingBuffer array contains another copy of the - first `1 << tail_bits' bytes: - buffer_[i] == buffer_[i + (1 << window_bits)], if i < (1 << tail_bits), - and another copy of the last two bytes: - buffer_[-1] == buffer_[(1 << window_bits) - 1] and - buffer_[-2] == buffer_[(1 << window_bits) - 2]. */ -typedef struct RingBuffer { - /* Size of the ring-buffer is (1 << window_bits) + tail_size_. */ - const uint32_t size_; - const uint32_t mask_; - const uint32_t tail_size_; - const uint32_t total_size_; - - uint32_t cur_size_; - /* Position to write in the ring buffer. */ - uint32_t pos_; - /* The actual ring buffer containing the copy of the last two bytes, the data, - and the copy of the beginning as a tail. */ - uint8_t* data_; - /* The start of the ring-buffer. */ - uint8_t* buffer_; -} RingBuffer; - -static BROTLI_INLINE void RingBufferInit(RingBuffer* rb) { - rb->cur_size_ = 0; - rb->pos_ = 0; - rb->data_ = 0; - rb->buffer_ = 0; -} - -static BROTLI_INLINE void RingBufferSetup( - const BrotliEncoderParams* params, RingBuffer* rb) { - int window_bits = ComputeRbBits(params); - int tail_bits = params->lgblock; - *(uint32_t*)&rb->size_ = 1u << window_bits; - *(uint32_t*)&rb->mask_ = (1u << window_bits) - 1; - *(uint32_t*)&rb->tail_size_ = 1u << tail_bits; - *(uint32_t*)&rb->total_size_ = rb->size_ + rb->tail_size_; -} - -static BROTLI_INLINE void RingBufferFree(MemoryManager* m, RingBuffer* rb) { - BROTLI_FREE(m, rb->data_); -} - -/* Allocates or re-allocates data_ to the given length + plus some slack - region before and after. Fills the slack regions with zeros. */ -static BROTLI_INLINE void RingBufferInitBuffer( - MemoryManager* m, const uint32_t buflen, RingBuffer* rb) { - static const size_t kSlackForEightByteHashingEverywhere = 7; - uint8_t* new_data = BROTLI_ALLOC( - m, uint8_t, 2 + buflen + kSlackForEightByteHashingEverywhere); - size_t i; - if (BROTLI_IS_OOM(m)) return; - if (rb->data_) { - memcpy(new_data, rb->data_, - 2 + rb->cur_size_ + kSlackForEightByteHashingEverywhere); - BROTLI_FREE(m, rb->data_); - } - rb->data_ = new_data; - rb->cur_size_ = buflen; - rb->buffer_ = rb->data_ + 2; - rb->buffer_[-2] = rb->buffer_[-1] = 0; - for (i = 0; i < kSlackForEightByteHashingEverywhere; ++i) { - rb->buffer_[rb->cur_size_ + i] = 0; - } -} - -static BROTLI_INLINE void RingBufferWriteTail( - const uint8_t* bytes, size_t n, RingBuffer* rb) { - const size_t masked_pos = rb->pos_ & rb->mask_; - if (BROTLI_PREDICT_FALSE(masked_pos < rb->tail_size_)) { - /* Just fill the tail buffer with the beginning data. */ - const size_t p = rb->size_ + masked_pos; - memcpy(&rb->buffer_[p], bytes, - BROTLI_MIN(size_t, n, rb->tail_size_ - masked_pos)); - } -} - -/* Push bytes into the ring buffer. */ -static BROTLI_INLINE void RingBufferWrite( - MemoryManager* m, const uint8_t* bytes, size_t n, RingBuffer* rb) { - if (rb->pos_ == 0 && n < rb->tail_size_) { - /* Special case for the first write: to process the first block, we don't - need to allocate the whole ring-buffer and we don't need the tail - either. However, we do this memory usage optimization only if the - first write is less than the tail size, which is also the input block - size, otherwise it is likely that other blocks will follow and we - will need to reallocate to the full size anyway. */ - rb->pos_ = (uint32_t)n; - RingBufferInitBuffer(m, rb->pos_, rb); - if (BROTLI_IS_OOM(m)) return; - memcpy(rb->buffer_, bytes, n); - return; - } - if (rb->cur_size_ < rb->total_size_) { - /* Lazily allocate the full buffer. */ - RingBufferInitBuffer(m, rb->total_size_, rb); - if (BROTLI_IS_OOM(m)) return; - /* Initialize the last two bytes to zero, so that we don't have to worry - later when we copy the last two bytes to the first two positions. */ - rb->buffer_[rb->size_ - 2] = 0; - rb->buffer_[rb->size_ - 1] = 0; - } - { - const size_t masked_pos = rb->pos_ & rb->mask_; - /* The length of the writes is limited so that we do not need to worry - about a write */ - RingBufferWriteTail(bytes, n, rb); - if (BROTLI_PREDICT_TRUE(masked_pos + n <= rb->size_)) { - /* A single write fits. */ - memcpy(&rb->buffer_[masked_pos], bytes, n); - } else { - /* Split into two writes. - Copy into the end of the buffer, including the tail buffer. */ - memcpy(&rb->buffer_[masked_pos], bytes, - BROTLI_MIN(size_t, n, rb->total_size_ - masked_pos)); - /* Copy into the beginning of the buffer */ - memcpy(&rb->buffer_[0], bytes + (rb->size_ - masked_pos), - n - (rb->size_ - masked_pos)); - } - } - { - BROTLI_BOOL not_first_lap = (rb->pos_ & (1u << 31)) != 0; - uint32_t rb_pos_mask = (1u << 31) - 1; - rb->buffer_[-2] = rb->buffer_[rb->size_ - 2]; - rb->buffer_[-1] = rb->buffer_[rb->size_ - 1]; - rb->pos_ = (rb->pos_ & rb_pos_mask) + (uint32_t)(n & rb_pos_mask); - if (not_first_lap) { - /* Wrap, but preserve not-a-first-lap feature. */ - rb->pos_ |= 1u << 31; - } - } -} - -#if defined(__cplusplus) || defined(c_plusplus) -} /* extern "C" */ -#endif - -#endif /* BROTLI_ENC_RINGBUFFER_H_ */ |