diff options
Diffstat (limited to 'src/core/channel/metadata_buffer.c')
| -rw-r--r-- | src/core/channel/metadata_buffer.c | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/src/core/channel/metadata_buffer.c b/src/core/channel/metadata_buffer.c new file mode 100644 index 0000000000..75fd90b707 --- /dev/null +++ b/src/core/channel/metadata_buffer.c @@ -0,0 +1,198 @@ +/* + * + * 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); +} |