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/*
*
* Copyright 2014, 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 "src/core/channel/metadata_buffer.h"
#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include <grpc/support/useful.h>
#include <string.h>
#define INITIAL_ELEM_CAP 8
/* One queued call; we track offsets to string data in a shared buffer to
reduce allocations. See grpc_metadata_buffer_impl for the memory use
strategy */
typedef struct {
grpc_mdelem *md;
void (*cb)(void *user_data, grpc_op_error error);
void *user_data;
gpr_uint32 flags;
} qelem;
/* Memory layout:
grpc_metadata_buffer_impl
followed by an array of qelem */
struct grpc_metadata_buffer_impl {
/* number of elements in q */
size_t elems;
/* capacity of q */
size_t elem_cap;
};
#define ELEMS(buffer) ((qelem *)((buffer)+1))
void grpc_metadata_buffer_init(grpc_metadata_buffer *buffer) {
/* start buffer as NULL, indicating no elements */
*buffer = NULL;
}
void grpc_metadata_buffer_destroy(grpc_metadata_buffer *buffer,
grpc_op_error error) {
size_t i;
qelem *qe;
if (*buffer) {
for (i = 0; i < (*buffer)->elems; i++) {
qe = &ELEMS(*buffer)[i];
grpc_mdelem_unref(qe->md);
qe->cb(qe->user_data, error);
}
gpr_free(*buffer);
}
}
void grpc_metadata_buffer_queue(grpc_metadata_buffer *buffer,
grpc_call_op *op) {
grpc_metadata_buffer_impl *impl = *buffer;
qelem *qe;
size_t bytes;
GPR_ASSERT(op->type == GRPC_SEND_METADATA || op->type == GRPC_RECV_METADATA);
if (!impl) {
/* this is the first element: allocate enough space to hold the
header object and the initial element capacity of qelems */
bytes =
sizeof(grpc_metadata_buffer_impl) + INITIAL_ELEM_CAP * sizeof(qelem);
impl = gpr_malloc(bytes);
/* initialize the header object */
impl->elems = 0;
impl->elem_cap = INITIAL_ELEM_CAP;
} else if (impl->elems == impl->elem_cap) {
/* more qelems than what we can deal with: grow by doubling size */
impl->elem_cap *= 2;
bytes = sizeof(grpc_metadata_buffer_impl) + impl->elem_cap * sizeof(qelem);
impl = gpr_realloc(impl, bytes);
}
/* append an element to the queue */
qe = &ELEMS(impl)[impl->elems];
impl->elems++;
qe->md = op->data.metadata;
qe->cb = op->done_cb;
qe->user_data = op->user_data;
qe->flags = op->flags;
/* header object may have changed location: store it back */
*buffer = impl;
}
void grpc_metadata_buffer_flush(grpc_metadata_buffer *buffer,
grpc_call_element *elem) {
grpc_metadata_buffer_impl *impl = *buffer;
grpc_call_op op;
qelem *qe;
size_t i;
if (!impl) {
/* nothing to send */
return;
}
/* construct call_op's, and push them down the stack */
op.type = GRPC_SEND_METADATA;
op.dir = GRPC_CALL_DOWN;
for (i = 0; i < impl->elems; i++) {
qe = &ELEMS(impl)[i];
op.done_cb = qe->cb;
op.user_data = qe->user_data;
op.flags = qe->flags;
op.data.metadata = qe->md;
grpc_call_next_op(elem, &op);
}
/* free data structures and reset to NULL: we can only flush once */
gpr_free(impl);
*buffer = NULL;
}
size_t grpc_metadata_buffer_count(const grpc_metadata_buffer *buffer) {
return *buffer ? (*buffer)->elems : 0;
}
typedef struct { grpc_metadata_buffer_impl *impl; } elems_hdr;
grpc_metadata *grpc_metadata_buffer_extract_elements(
grpc_metadata_buffer *buffer) {
grpc_metadata_buffer_impl *impl;
elems_hdr *hdr;
qelem *src;
grpc_metadata *out;
size_t i;
impl = *buffer;
if (!impl) {
return NULL;
}
hdr = gpr_malloc(sizeof(elems_hdr) + impl->elems * sizeof(grpc_metadata));
src = ELEMS(impl);
out = (grpc_metadata *)(hdr + 1);
hdr->impl = impl;
for (i = 0; i < impl->elems; i++) {
out[i].key = (char *)grpc_mdstr_as_c_string(src[i].md->key);
out[i].value = (char *)grpc_mdstr_as_c_string(src[i].md->value);
out[i].value_length = GPR_SLICE_LENGTH(src[i].md->value->slice);
}
/* clear out buffer (it's not possible to extract elements twice */
*buffer = NULL;
return out;
}
void grpc_metadata_buffer_cleanup_elements(void *elements,
grpc_op_error error) {
elems_hdr *hdr = ((elems_hdr *)elements) - 1;
if (!elements) {
return;
}
grpc_metadata_buffer_destroy(&hdr->impl, error);
gpr_free(hdr);
}
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