| /* |
| * |
| * Copyright 2015, Google Inc. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: |
| * |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following disclaimer |
| * in the documentation and/or other materials provided with the |
| * distribution. |
| * * Neither the name of Google Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| * |
| */ |
| |
| #include <grpc/support/port_platform.h> |
| #include <grpc/support/slice_buffer.h> |
| |
| #include <string.h> |
| |
| #include <grpc/support/alloc.h> |
| #include <grpc/support/log.h> |
| #include <grpc/support/useful.h> |
| |
| /* grow a buffer; requires GRPC_SLICE_BUFFER_INLINE_ELEMENTS > 1 */ |
| #define GROW(x) (3 * (x) / 2) |
| |
| static void maybe_embiggen(gpr_slice_buffer *sb) { |
| if (sb->count == sb->capacity) { |
| sb->capacity = GROW(sb->capacity); |
| GPR_ASSERT(sb->capacity > sb->count); |
| if (sb->slices == sb->inlined) { |
| sb->slices = gpr_malloc(sb->capacity * sizeof(gpr_slice)); |
| memcpy(sb->slices, sb->inlined, sb->count * sizeof(gpr_slice)); |
| } else { |
| sb->slices = gpr_realloc(sb->slices, sb->capacity * sizeof(gpr_slice)); |
| } |
| } |
| } |
| |
| void gpr_slice_buffer_init(gpr_slice_buffer *sb) { |
| sb->count = 0; |
| sb->length = 0; |
| sb->capacity = GRPC_SLICE_BUFFER_INLINE_ELEMENTS; |
| sb->slices = sb->inlined; |
| } |
| |
| void gpr_slice_buffer_destroy(gpr_slice_buffer *sb) { |
| gpr_slice_buffer_reset_and_unref(sb); |
| if (sb->slices != sb->inlined) { |
| gpr_free(sb->slices); |
| } |
| } |
| |
| uint8_t *gpr_slice_buffer_tiny_add(gpr_slice_buffer *sb, size_t n) { |
| gpr_slice *back; |
| uint8_t *out; |
| |
| sb->length += n; |
| |
| if (sb->count == 0) goto add_new; |
| back = &sb->slices[sb->count - 1]; |
| if (back->refcount) goto add_new; |
| if ((back->data.inlined.length + n) > sizeof(back->data.inlined.bytes)) |
| goto add_new; |
| out = back->data.inlined.bytes + back->data.inlined.length; |
| back->data.inlined.length = (uint8_t)(back->data.inlined.length + n); |
| return out; |
| |
| add_new: |
| maybe_embiggen(sb); |
| back = &sb->slices[sb->count]; |
| sb->count++; |
| back->refcount = NULL; |
| back->data.inlined.length = (uint8_t)n; |
| return back->data.inlined.bytes; |
| } |
| |
| size_t gpr_slice_buffer_add_indexed(gpr_slice_buffer *sb, gpr_slice s) { |
| size_t out = sb->count; |
| maybe_embiggen(sb); |
| sb->slices[out] = s; |
| sb->length += GPR_SLICE_LENGTH(s); |
| sb->count = out + 1; |
| return out; |
| } |
| |
| void gpr_slice_buffer_add(gpr_slice_buffer *sb, gpr_slice s) { |
| size_t n = sb->count; |
| /* if both the last slice in the slice buffer and the slice being added |
| are inlined (that is, that they carry their data inside the slice data |
| structure), and the back slice is not full, then concatenate directly |
| into the back slice, preventing many small slices being passed into |
| writes */ |
| if (!s.refcount && n) { |
| gpr_slice *back = &sb->slices[n - 1]; |
| if (!back->refcount && back->data.inlined.length < GPR_SLICE_INLINED_SIZE) { |
| if (s.data.inlined.length + back->data.inlined.length <= |
| GPR_SLICE_INLINED_SIZE) { |
| memcpy(back->data.inlined.bytes + back->data.inlined.length, |
| s.data.inlined.bytes, s.data.inlined.length); |
| back->data.inlined.length = |
| (uint8_t)(back->data.inlined.length + s.data.inlined.length); |
| } else { |
| size_t cp1 = GPR_SLICE_INLINED_SIZE - back->data.inlined.length; |
| memcpy(back->data.inlined.bytes + back->data.inlined.length, |
| s.data.inlined.bytes, cp1); |
| back->data.inlined.length = GPR_SLICE_INLINED_SIZE; |
| maybe_embiggen(sb); |
| back = &sb->slices[n]; |
| sb->count = n + 1; |
| back->refcount = NULL; |
| back->data.inlined.length = (uint8_t)(s.data.inlined.length - cp1); |
| memcpy(back->data.inlined.bytes, s.data.inlined.bytes + cp1, |
| s.data.inlined.length - cp1); |
| } |
| sb->length += s.data.inlined.length; |
| return; /* early out */ |
| } |
| } |
| gpr_slice_buffer_add_indexed(sb, s); |
| } |
| |
| void gpr_slice_buffer_addn(gpr_slice_buffer *sb, gpr_slice *s, size_t n) { |
| size_t i; |
| for (i = 0; i < n; i++) { |
| gpr_slice_buffer_add(sb, s[i]); |
| } |
| } |
| |
| void gpr_slice_buffer_pop(gpr_slice_buffer *sb) { |
| if (sb->count != 0) { |
| size_t count = --sb->count; |
| sb->length -= GPR_SLICE_LENGTH(sb->slices[count]); |
| } |
| } |
| |
| void gpr_slice_buffer_reset_and_unref(gpr_slice_buffer *sb) { |
| size_t i; |
| |
| for (i = 0; i < sb->count; i++) { |
| gpr_slice_unref(sb->slices[i]); |
| } |
| |
| sb->count = 0; |
| sb->length = 0; |
| } |
| |
| void gpr_slice_buffer_swap(gpr_slice_buffer *a, gpr_slice_buffer *b) { |
| GPR_SWAP(size_t, a->count, b->count); |
| GPR_SWAP(size_t, a->capacity, b->capacity); |
| GPR_SWAP(size_t, a->length, b->length); |
| |
| if (a->slices == a->inlined) { |
| if (b->slices == b->inlined) { |
| /* swap contents of inlined buffer */ |
| gpr_slice temp[GRPC_SLICE_BUFFER_INLINE_ELEMENTS]; |
| memcpy(temp, a->slices, b->count * sizeof(gpr_slice)); |
| memcpy(a->slices, b->slices, a->count * sizeof(gpr_slice)); |
| memcpy(b->slices, temp, b->count * sizeof(gpr_slice)); |
| } else { |
| /* a is inlined, b is not - copy a inlined into b, fix pointers */ |
| a->slices = b->slices; |
| b->slices = b->inlined; |
| memcpy(b->slices, a->inlined, b->count * sizeof(gpr_slice)); |
| } |
| } else if (b->slices == b->inlined) { |
| /* b is inlined, a is not - copy b inlined int a, fix pointers */ |
| b->slices = a->slices; |
| a->slices = a->inlined; |
| memcpy(a->slices, b->inlined, a->count * sizeof(gpr_slice)); |
| } else { |
| /* no inlining: easy swap */ |
| GPR_SWAP(gpr_slice *, a->slices, b->slices); |
| } |
| } |
| |
| void gpr_slice_buffer_move_into(gpr_slice_buffer *src, gpr_slice_buffer *dst) { |
| /* anything to move? */ |
| if (src->count == 0) { |
| return; |
| } |
| /* anything in dst? */ |
| if (dst->count == 0) { |
| gpr_slice_buffer_swap(src, dst); |
| return; |
| } |
| /* both buffers have data - copy, and reset src */ |
| gpr_slice_buffer_addn(dst, src->slices, src->count); |
| src->count = 0; |
| src->length = 0; |
| } |
| |
| void gpr_slice_buffer_move_first(gpr_slice_buffer *src, size_t n, |
| gpr_slice_buffer *dst) { |
| size_t src_idx; |
| size_t output_len = dst->length + n; |
| size_t new_input_len = src->length - n; |
| GPR_ASSERT(src->length >= n); |
| if (src->length == n) { |
| gpr_slice_buffer_move_into(src, dst); |
| return; |
| } |
| src_idx = 0; |
| while (src_idx < src->capacity) { |
| gpr_slice slice = src->slices[src_idx]; |
| size_t slice_len = GPR_SLICE_LENGTH(slice); |
| if (n > slice_len) { |
| gpr_slice_buffer_add(dst, slice); |
| n -= slice_len; |
| src_idx++; |
| } else if (n == slice_len) { |
| gpr_slice_buffer_add(dst, slice); |
| src_idx++; |
| break; |
| } else { /* n < slice_len */ |
| src->slices[src_idx] = gpr_slice_split_tail(&slice, n); |
| GPR_ASSERT(GPR_SLICE_LENGTH(slice) == n); |
| GPR_ASSERT(GPR_SLICE_LENGTH(src->slices[src_idx]) == slice_len - n); |
| gpr_slice_buffer_add(dst, slice); |
| break; |
| } |
| } |
| GPR_ASSERT(dst->length == output_len); |
| memmove(src->slices, src->slices + src_idx, |
| sizeof(gpr_slice) * (src->count - src_idx)); |
| src->count -= src_idx; |
| src->length = new_input_len; |
| GPR_ASSERT(src->count > 0); |
| } |
| |
| void gpr_slice_buffer_trim_end(gpr_slice_buffer *sb, size_t n, |
| gpr_slice_buffer *garbage) { |
| GPR_ASSERT(n <= sb->length); |
| sb->length -= n; |
| for (;;) { |
| size_t idx = sb->count - 1; |
| gpr_slice slice = sb->slices[idx]; |
| size_t slice_len = GPR_SLICE_LENGTH(slice); |
| if (slice_len > n) { |
| sb->slices[idx] = gpr_slice_split_head(&slice, slice_len - n); |
| gpr_slice_buffer_add_indexed(garbage, slice); |
| return; |
| } else if (slice_len == n) { |
| gpr_slice_buffer_add_indexed(garbage, slice); |
| sb->count = idx; |
| return; |
| } else { |
| gpr_slice_buffer_add_indexed(garbage, slice); |
| n -= slice_len; |
| sb->count = idx; |
| } |
| } |
| } |
| |
| gpr_slice gpr_slice_buffer_take_first(gpr_slice_buffer *sb) { |
| gpr_slice slice; |
| GPR_ASSERT(sb->count > 0); |
| slice = sb->slices[0]; |
| memmove(&sb->slices[0], &sb->slices[1], (sb->count - 1) * sizeof(gpr_slice)); |
| sb->count--; |
| sb->length -= GPR_SLICE_LENGTH(slice); |
| return slice; |
| } |