--- /dev/null
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * 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.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+
+#include <grpc/slice_buffer.h>
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+
+#include "src/core/lib/gpr/useful.h"
+#include "src/core/lib/iomgr/exec_ctx.h"
+#include "src/core/lib/slice/slice_internal.h"
+
+/* grow a buffer; requires GRPC_SLICE_BUFFER_INLINE_ELEMENTS > 1 */
+#define GROW(x) (3 * (x) / 2)
+
+/* Typically, we do not actually need to embiggen (by calling
+ * memmove/malloc/realloc) - only if we were up against the full capacity of the
+ * slice buffer. If do_embiggen is inlined, the compiler clobbers multiple
+ * registers pointlessly in the common case. */
+static void GPR_ATTRIBUTE_NOINLINE do_embiggen(grpc_slice_buffer* sb,
+ const size_t slice_count,
+ const size_t slice_offset) {
+ if (slice_offset != 0) {
+ /* Make room by moving elements if there's still space unused */
+ memmove(sb->base_slices, sb->slices, sb->count * sizeof(grpc_slice));
+ sb->slices = sb->base_slices;
+ } else {
+ /* Allocate more memory if no more space is available */
+ const size_t new_capacity = GROW(sb->capacity);
+ sb->capacity = new_capacity;
+ if (sb->base_slices == sb->inlined) {
+ sb->base_slices = static_cast<grpc_slice*>(
+ gpr_malloc(new_capacity * sizeof(grpc_slice)));
+ memcpy(sb->base_slices, sb->inlined, slice_count * sizeof(grpc_slice));
+ } else {
+ sb->base_slices = static_cast<grpc_slice*>(
+ gpr_realloc(sb->base_slices, new_capacity * sizeof(grpc_slice)));
+ }
+
+ sb->slices = sb->base_slices + slice_offset;
+ }
+}
+
+static void maybe_embiggen(grpc_slice_buffer* sb) {
+ if (sb->count == 0) {
+ sb->slices = sb->base_slices;
+ return;
+ }
+
+ /* How far away from sb->base_slices is sb->slices pointer */
+ size_t slice_offset = static_cast<size_t>(sb->slices - sb->base_slices);
+ size_t slice_count = sb->count + slice_offset;
+ if (GPR_UNLIKELY(slice_count == sb->capacity)) {
+ do_embiggen(sb, slice_count, slice_offset);
+ }
+}
+
+void grpc_slice_buffer_init(grpc_slice_buffer* sb) {
+ sb->count = 0;
+ sb->length = 0;
+ sb->capacity = GRPC_SLICE_BUFFER_INLINE_ELEMENTS;
+ sb->base_slices = sb->slices = sb->inlined;
+}
+
+void grpc_slice_buffer_destroy_internal(grpc_slice_buffer* sb) {
+ grpc_slice_buffer_reset_and_unref_internal(sb);
+ if (sb->base_slices != sb->inlined) {
+ gpr_free(sb->base_slices);
+ }
+}
+
+void grpc_slice_buffer_destroy(grpc_slice_buffer* sb) {
+ if (grpc_core::ExecCtx::Get() == nullptr) {
+ grpc_core::ExecCtx exec_ctx;
+ grpc_slice_buffer_destroy_internal(sb);
+ } else {
+ grpc_slice_buffer_destroy_internal(sb);
+ }
+}
+
+uint8_t* grpc_slice_buffer_tiny_add(grpc_slice_buffer* sb, size_t n) {
+ grpc_slice* back;
+ uint8_t* out;
+
+ sb->length += n;
+
+ if (sb->count == 0) goto add_first;
+ 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 =
+ static_cast<uint8_t>(back->data.inlined.length + n);
+ return out;
+
+add_new:
+ maybe_embiggen(sb);
+add_first:
+ back = &sb->slices[sb->count];
+ sb->count++;
+ back->refcount = nullptr;
+ back->data.inlined.length = static_cast<uint8_t>(n);
+ return back->data.inlined.bytes;
+}
+
+size_t grpc_slice_buffer_add_indexed(grpc_slice_buffer* sb, grpc_slice s) {
+ size_t out = sb->count;
+ maybe_embiggen(sb);
+ sb->slices[out] = s;
+ sb->length += GRPC_SLICE_LENGTH(s);
+ sb->count = out + 1;
+ return out;
+}
+
+void grpc_slice_buffer_add(grpc_slice_buffer* sb, grpc_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) {
+ grpc_slice* back = &sb->slices[n - 1];
+ if (!back->refcount &&
+ back->data.inlined.length < GRPC_SLICE_INLINED_SIZE) {
+ if (s.data.inlined.length + back->data.inlined.length <=
+ GRPC_SLICE_INLINED_SIZE) {
+ memcpy(back->data.inlined.bytes + back->data.inlined.length,
+ s.data.inlined.bytes, s.data.inlined.length);
+ back->data.inlined.length = static_cast<uint8_t>(
+ back->data.inlined.length + s.data.inlined.length);
+ } else {
+ size_t cp1 = GRPC_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 = GRPC_SLICE_INLINED_SIZE;
+ maybe_embiggen(sb);
+ back = &sb->slices[n];
+ sb->count = n + 1;
+ back->refcount = nullptr;
+ back->data.inlined.length =
+ static_cast<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 */
+ }
+ }
+ grpc_slice_buffer_add_indexed(sb, s);
+}
+
+void grpc_slice_buffer_addn(grpc_slice_buffer* sb, grpc_slice* s, size_t n) {
+ size_t i;
+ for (i = 0; i < n; i++) {
+ grpc_slice_buffer_add(sb, s[i]);
+ }
+}
+
+void grpc_slice_buffer_pop(grpc_slice_buffer* sb) {
+ if (sb->count != 0) {
+ size_t count = --sb->count;
+ sb->length -= GRPC_SLICE_LENGTH(sb->slices[count]);
+ }
+}
+
+void grpc_slice_buffer_reset_and_unref_internal(grpc_slice_buffer* sb) {
+ size_t i;
+ for (i = 0; i < sb->count; i++) {
+ grpc_slice_unref_internal(sb->slices[i]);
+ }
+
+ sb->count = 0;
+ sb->length = 0;
+ sb->slices = sb->base_slices;
+}
+
+void grpc_slice_buffer_reset_and_unref(grpc_slice_buffer* sb) {
+ if (grpc_core::ExecCtx::Get() == nullptr) {
+ grpc_core::ExecCtx exec_ctx;
+ grpc_slice_buffer_reset_and_unref_internal(sb);
+ } else {
+ grpc_slice_buffer_reset_and_unref_internal(sb);
+ }
+}
+
+void grpc_slice_buffer_swap(grpc_slice_buffer* a, grpc_slice_buffer* b) {
+ size_t a_offset = static_cast<size_t>(a->slices - a->base_slices);
+ size_t b_offset = static_cast<size_t>(b->slices - b->base_slices);
+
+ size_t a_count = a->count + a_offset;
+ size_t b_count = b->count + b_offset;
+
+ if (a->base_slices == a->inlined) {
+ if (b->base_slices == b->inlined) {
+ /* swap contents of inlined buffer */
+ grpc_slice temp[GRPC_SLICE_BUFFER_INLINE_ELEMENTS];
+ memcpy(temp, a->base_slices, a_count * sizeof(grpc_slice));
+ memcpy(a->base_slices, b->base_slices, b_count * sizeof(grpc_slice));
+ memcpy(b->base_slices, temp, a_count * sizeof(grpc_slice));
+ } else {
+ /* a is inlined, b is not - copy a inlined into b, fix pointers */
+ a->base_slices = b->base_slices;
+ b->base_slices = b->inlined;
+ memcpy(b->base_slices, a->inlined, a_count * sizeof(grpc_slice));
+ }
+ } else if (b->base_slices == b->inlined) {
+ /* b is inlined, a is not - copy b inlined int a, fix pointers */
+ b->base_slices = a->base_slices;
+ a->base_slices = a->inlined;
+ memcpy(a->base_slices, b->inlined, b_count * sizeof(grpc_slice));
+ } else {
+ /* no inlining: easy swap */
+ GPR_SWAP(grpc_slice*, a->base_slices, b->base_slices);
+ }
+
+ /* Update the slices pointers (cannot do a GPR_SWAP on slices fields here).
+ * Also note that since the base_slices pointers are already swapped we need
+ * use 'b_offset' for 'a->base_slices' and vice versa */
+ a->slices = a->base_slices + b_offset;
+ b->slices = b->base_slices + a_offset;
+
+ /* base_slices and slices fields are correctly set. Swap all other fields */
+ GPR_SWAP(size_t, a->count, b->count);
+ GPR_SWAP(size_t, a->capacity, b->capacity);
+ GPR_SWAP(size_t, a->length, b->length);
+}
+
+void grpc_slice_buffer_move_into(grpc_slice_buffer* src,
+ grpc_slice_buffer* dst) {
+ /* anything to move? */
+ if (src->count == 0) {
+ return;
+ }
+ /* anything in dst? */
+ if (dst->count == 0) {
+ grpc_slice_buffer_swap(src, dst);
+ return;
+ }
+ /* both buffers have data - copy, and reset src */
+ grpc_slice_buffer_addn(dst, src->slices, src->count);
+ src->count = 0;
+ src->length = 0;
+}
+
+template <bool incref>
+static void slice_buffer_move_first_maybe_ref(grpc_slice_buffer* src, size_t n,
+ grpc_slice_buffer* dst) {
+ GPR_ASSERT(src->length >= n);
+ if (src->length == n) {
+ grpc_slice_buffer_move_into(src, dst);
+ return;
+ }
+
+ size_t output_len = dst->length + n;
+ size_t new_input_len = src->length - n;
+
+ while (src->count > 0) {
+ grpc_slice slice = grpc_slice_buffer_take_first(src);
+ size_t slice_len = GRPC_SLICE_LENGTH(slice);
+ if (n > slice_len) {
+ grpc_slice_buffer_add(dst, slice);
+ n -= slice_len;
+ } else if (n == slice_len) {
+ grpc_slice_buffer_add(dst, slice);
+ break;
+ } else if (incref) { /* n < slice_len */
+ grpc_slice_buffer_undo_take_first(
+ src, grpc_slice_split_tail_maybe_ref(&slice, n, GRPC_SLICE_REF_BOTH));
+ GPR_ASSERT(GRPC_SLICE_LENGTH(slice) == n);
+ grpc_slice_buffer_add(dst, slice);
+ break;
+ } else { /* n < slice_len */
+ grpc_slice_buffer_undo_take_first(
+ src, grpc_slice_split_tail_maybe_ref(&slice, n, GRPC_SLICE_REF_TAIL));
+ GPR_ASSERT(GRPC_SLICE_LENGTH(slice) == n);
+ grpc_slice_buffer_add_indexed(dst, slice);
+ break;
+ }
+ }
+ GPR_ASSERT(dst->length == output_len);
+ GPR_ASSERT(src->length == new_input_len);
+ GPR_ASSERT(src->count > 0);
+}
+
+void grpc_slice_buffer_move_first(grpc_slice_buffer* src, size_t n,
+ grpc_slice_buffer* dst) {
+ slice_buffer_move_first_maybe_ref<true>(src, n, dst);
+}
+
+void grpc_slice_buffer_move_first_no_ref(grpc_slice_buffer* src, size_t n,
+ grpc_slice_buffer* dst) {
+ slice_buffer_move_first_maybe_ref<false>(src, n, dst);
+}
+
+void grpc_slice_buffer_move_first_into_buffer(grpc_slice_buffer* src, size_t n,
+ void* dst) {
+ char* dstp = static_cast<char*>(dst);
+ GPR_ASSERT(src->length >= n);
+
+ while (n > 0) {
+ grpc_slice slice = grpc_slice_buffer_take_first(src);
+ size_t slice_len = GRPC_SLICE_LENGTH(slice);
+ if (slice_len > n) {
+ memcpy(dstp, GRPC_SLICE_START_PTR(slice), n);
+ grpc_slice_buffer_undo_take_first(
+ src, grpc_slice_sub_no_ref(slice, n, slice_len));
+ n = 0;
+ } else if (slice_len == n) {
+ memcpy(dstp, GRPC_SLICE_START_PTR(slice), n);
+ grpc_slice_unref_internal(slice);
+ n = 0;
+ } else {
+ memcpy(dstp, GRPC_SLICE_START_PTR(slice), slice_len);
+ dstp += slice_len;
+ n -= slice_len;
+ grpc_slice_unref_internal(slice);
+ }
+ }
+}
+
+void grpc_slice_buffer_trim_end(grpc_slice_buffer* sb, size_t n,
+ grpc_slice_buffer* garbage) {
+ GPR_ASSERT(n <= sb->length);
+ sb->length -= n;
+ for (;;) {
+ size_t idx = sb->count - 1;
+ grpc_slice slice = sb->slices[idx];
+ size_t slice_len = GRPC_SLICE_LENGTH(slice);
+ if (slice_len > n) {
+ sb->slices[idx] = grpc_slice_split_head(&slice, slice_len - n);
+ if (garbage) {
+ grpc_slice_buffer_add_indexed(garbage, slice);
+ } else {
+ grpc_slice_unref_internal(slice);
+ }
+ return;
+ } else if (slice_len == n) {
+ if (garbage) {
+ grpc_slice_buffer_add_indexed(garbage, slice);
+ } else {
+ grpc_slice_unref_internal(slice);
+ }
+ sb->count = idx;
+ return;
+ } else {
+ if (garbage) {
+ grpc_slice_buffer_add_indexed(garbage, slice);
+ } else {
+ grpc_slice_unref_internal(slice);
+ }
+ n -= slice_len;
+ sb->count = idx;
+ }
+ }
+}
+
+grpc_slice grpc_slice_buffer_take_first(grpc_slice_buffer* sb) {
+ grpc_slice slice;
+ GPR_ASSERT(sb->count > 0);
+ slice = sb->slices[0];
+ sb->slices++;
+ sb->count--;
+ sb->length -= GRPC_SLICE_LENGTH(slice);
+
+ return slice;
+}
+
+void grpc_slice_buffer_remove_first(grpc_slice_buffer* sb) {
+ GPR_DEBUG_ASSERT(sb->count > 0);
+ sb->length -= GRPC_SLICE_LENGTH(sb->slices[0]);
+ grpc_slice_unref_internal(sb->slices[0]);
+ sb->slices++;
+ if (--sb->count == 0) {
+ sb->slices = sb->base_slices;
+ }
+}
+
+void grpc_slice_buffer_sub_first(grpc_slice_buffer* sb, size_t begin,
+ size_t end) {
+ // TODO(soheil): Introduce a ptr version for sub.
+ sb->length -= GRPC_SLICE_LENGTH(sb->slices[0]);
+ sb->slices[0] = grpc_slice_sub_no_ref(sb->slices[0], begin, end);
+ sb->length += end - begin;
+}
+
+void grpc_slice_buffer_undo_take_first(grpc_slice_buffer* sb,
+ grpc_slice slice) {
+ sb->slices--;
+ sb->slices[0] = slice;
+ sb->count++;
+ sb->length += GRPC_SLICE_LENGTH(slice);
+}
git://repos.xcallymotion.com / motion2.git / blobdiff