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-rw-r--r--src/core/lib/support/slice_buffer.c282
1 files changed, 282 insertions, 0 deletions
diff --git a/src/core/lib/support/slice_buffer.c b/src/core/lib/support/slice_buffer.c
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+++ b/src/core/lib/support/slice_buffer.c
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+/*
+ *
+ * Copyright 2015-2016, 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;
+}
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