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314 lines
11 KiB
314 lines
11 KiB
/* |
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* |
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* Copyright 2016, Google Inc. |
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* All rights reserved. |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions are |
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* met: |
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* |
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* * Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* * Redistributions in binary form must reproduce the above |
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* copyright notice, this list of conditions and the following disclaimer |
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* in the documentation and/or other materials provided with the |
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* distribution. |
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* * Neither the name of Google Inc. nor the names of its |
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* contributors may be used to endorse or promote products derived from |
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* this software without specific prior written permission. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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* |
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*/ |
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#include "src/core/ext/census/resource.h" |
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#include "third_party/nanopb/pb_decode.h" |
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#include <grpc/census.h> |
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#include <grpc/support/alloc.h> |
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#include <grpc/support/log.h> |
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#include <grpc/support/sync.h> |
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#include <stdbool.h> |
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#include <string.h> |
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// Protect local resource data structures. |
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static gpr_mu resource_lock; |
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// Deleteing and creating resources are relatively rare events, and should not |
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// be done in the critical path of performance sensitive code. We record |
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// current resource id's used in a simple array, and just search it each time |
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// we need to assign a new id, or look up a resource. |
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static resource **resources = NULL; |
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// Number of entries in *resources |
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static size_t n_resources = 0; |
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// Number of defined resources |
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static size_t n_defined_resources = 0; |
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void initialize_resources(void) { |
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gpr_mu_init(&resource_lock); |
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gpr_mu_lock(&resource_lock); |
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GPR_ASSERT(resources == NULL && n_resources == 0 && n_defined_resources == 0); |
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gpr_mu_unlock(&resource_lock); |
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} |
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// Delete a resource given it's ID. The ID must be a valid resource ID. Must be |
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// called with resource_lock held. |
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static void delete_resource_locked(size_t rid) { |
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GPR_ASSERT(resources[rid] != NULL); |
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gpr_free(resources[rid]->name); |
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gpr_free(resources[rid]->description); |
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gpr_free(resources[rid]->numerators); |
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gpr_free(resources[rid]->denominators); |
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gpr_free(resources[rid]); |
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resources[rid] = NULL; |
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n_defined_resources--; |
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} |
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void shutdown_resources(void) { |
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gpr_mu_lock(&resource_lock); |
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for (size_t i = 0; i < n_resources; i++) { |
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if (resources[i] != NULL) { |
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delete_resource_locked(i); |
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} |
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} |
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GPR_ASSERT(n_defined_resources == 0); |
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gpr_free(resources); |
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resources = NULL; |
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n_resources = 0; |
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gpr_mu_unlock(&resource_lock); |
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} |
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// Check the contents of string fields in a resource proto. |
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static bool validate_string(pb_istream_t *stream, const pb_field_t *field, |
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void **arg) { |
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resource *vresource = (resource *)*arg; |
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switch (field->tag) { |
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case google_census_Resource_name_tag: |
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// Name must have at least one character |
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if (stream->bytes_left == 0) { |
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gpr_log(GPR_INFO, "Zero-length Resource name."); |
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return false; |
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} |
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vresource->name = gpr_malloc(stream->bytes_left + 1); |
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vresource->name[stream->bytes_left] = '\0'; |
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if (!pb_read(stream, (uint8_t *)vresource->name, stream->bytes_left)) { |
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return false; |
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} |
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// Can't have same name as an existing resource. |
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for (size_t i = 0; i < n_resources; i++) { |
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resource *compare = resources[i]; |
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if (compare == vresource || compare == NULL) continue; |
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if (strcmp(compare->name, vresource->name) == 0) { |
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gpr_log(GPR_INFO, "Duplicate Resource name %s.", vresource->name); |
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return false; |
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} |
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} |
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break; |
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case google_census_Resource_description_tag: |
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if (stream->bytes_left == 0) { |
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return true; |
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} |
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vresource->description = gpr_malloc(stream->bytes_left + 1); |
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vresource->description[stream->bytes_left] = '\0'; |
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if (!pb_read(stream, (uint8_t *)vresource->description, |
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stream->bytes_left)) { |
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return false; |
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} |
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break; |
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default: |
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// No other string fields in Resource. Print warning and skip. |
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gpr_log(GPR_INFO, "Unknown string field type in Resource protobuf."); |
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if (!pb_read(stream, NULL, stream->bytes_left)) { |
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return false; |
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} |
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break; |
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} |
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return true; |
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} |
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// Decode numerators/denominators in a stream. The `count` and `bup` |
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// (BasicUnit pointer) are pointers to the approriate fields in a resource |
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// struct. |
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static bool validate_units_helper(pb_istream_t *stream, int *count, |
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google_census_Resource_BasicUnit **bup) { |
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while (stream->bytes_left) { |
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(*count)++; |
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// Have to allocate a new array of values. Normal case is 0 or 1, so |
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// this should normally not be an issue. |
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google_census_Resource_BasicUnit *new_bup = |
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gpr_malloc((size_t)*count * sizeof(google_census_Resource_BasicUnit)); |
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if (*count != 1) { |
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memcpy(new_bup, *bup, |
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(size_t)(*count - 1) * sizeof(google_census_Resource_BasicUnit)); |
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gpr_free(*bup); |
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} |
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*bup = new_bup; |
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uint64_t value; |
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if (!pb_decode_varint(stream, &value)) { |
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return false; |
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} |
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*(*bup + *count - 1) = (google_census_Resource_BasicUnit)value; |
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} |
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return true; |
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} |
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// Validate units field of a Resource proto. |
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static bool validate_units(pb_istream_t *stream, const pb_field_t *field, |
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void **arg) { |
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resource *vresource = (resource *)(*arg); |
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switch (field->tag) { |
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case google_census_Resource_MeasurementUnit_numerator_tag: |
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return validate_units_helper(stream, &vresource->n_numerators, |
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&vresource->numerators); |
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break; |
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case google_census_Resource_MeasurementUnit_denominator_tag: |
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return validate_units_helper(stream, &vresource->n_denominators, |
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&vresource->denominators); |
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break; |
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default: |
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gpr_log(GPR_ERROR, "Unknown field type."); |
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return false; |
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break; |
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} |
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return true; |
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} |
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// Validate the contents of a Resource proto. `id` is the intended resource id. |
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static bool validate_resource_pb(const uint8_t *resource_pb, |
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size_t resource_pb_size, size_t id) { |
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GPR_ASSERT(id < n_resources); |
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if (resource_pb == NULL) { |
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return false; |
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} |
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google_census_Resource vresource; |
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vresource.name.funcs.decode = &validate_string; |
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vresource.name.arg = resources[id]; |
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vresource.description.funcs.decode = &validate_string; |
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vresource.description.arg = resources[id]; |
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vresource.unit.numerator.funcs.decode = &validate_units; |
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vresource.unit.numerator.arg = resources[id]; |
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vresource.unit.denominator.funcs.decode = &validate_units; |
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vresource.unit.denominator.arg = resources[id]; |
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pb_istream_t stream = |
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pb_istream_from_buffer((uint8_t *)resource_pb, resource_pb_size); |
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if (!pb_decode(&stream, google_census_Resource_fields, &vresource)) { |
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return false; |
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} |
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// A Resource must have a name, a unit, with at least one numerator. |
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return (resources[id]->name != NULL && vresource.has_unit && |
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resources[id]->n_numerators > 0); |
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} |
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// Allocate a blank resource, and return associated ID. Must be called with |
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// resource_lock held. |
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size_t allocate_resource(void) { |
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// use next_id to optimize expected placement of next new resource. |
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static size_t next_id = 0; |
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size_t id = n_resources; // resource ID - initialize to invalid value. |
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// Expand resources if needed. |
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if (n_resources == n_defined_resources) { |
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size_t new_n_resources = n_resources ? n_resources * 2 : 2; |
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resource **new_resources = gpr_malloc(new_n_resources * sizeof(resource *)); |
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if (n_resources != 0) { |
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memcpy(new_resources, resources, n_resources * sizeof(resource *)); |
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} |
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memset(new_resources + n_resources, 0, |
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(new_n_resources - n_resources) * sizeof(resource *)); |
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gpr_free(resources); |
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resources = new_resources; |
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n_resources = new_n_resources; |
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id = n_defined_resources; |
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} else { |
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GPR_ASSERT(n_defined_resources < n_resources); |
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// Find a free id. |
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for (size_t base = 0; base < n_resources; base++) { |
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id = (next_id + base) % n_resources; |
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if (resources[id] == NULL) break; |
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} |
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} |
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GPR_ASSERT(id < n_resources && resources[id] == NULL); |
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resources[id] = gpr_malloc(sizeof(resource)); |
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memset(resources[id], 0, sizeof(resource)); |
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n_defined_resources++; |
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next_id = (id + 1) % n_resources; |
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return id; |
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} |
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int32_t census_define_resource(const uint8_t *resource_pb, |
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size_t resource_pb_size) { |
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if (resource_pb == NULL) { |
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return -1; |
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} |
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gpr_mu_lock(&resource_lock); |
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size_t id = allocate_resource(); |
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// Validate pb, extract name. |
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if (!validate_resource_pb(resource_pb, resource_pb_size, id)) { |
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delete_resource_locked(id); |
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gpr_mu_unlock(&resource_lock); |
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return -1; |
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} |
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gpr_mu_unlock(&resource_lock); |
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return (int32_t)id; |
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} |
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void census_delete_resource(int32_t rid) { |
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gpr_mu_lock(&resource_lock); |
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if (rid >= 0 && (size_t)rid < n_resources && resources[rid] != NULL) { |
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delete_resource_locked((size_t)rid); |
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} |
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gpr_mu_unlock(&resource_lock); |
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} |
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int32_t census_resource_id(const char *name) { |
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gpr_mu_lock(&resource_lock); |
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for (int32_t id = 0; (size_t)id < n_resources; id++) { |
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if (resources[id] != NULL && strcmp(resources[id]->name, name) == 0) { |
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gpr_mu_unlock(&resource_lock); |
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return id; |
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} |
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} |
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gpr_mu_unlock(&resource_lock); |
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return -1; |
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} |
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int32_t define_resource(const resource *base) { |
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GPR_ASSERT(base != NULL && base->name != NULL && base->n_numerators > 0 && |
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base->numerators != NULL); |
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gpr_mu_lock(&resource_lock); |
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size_t id = allocate_resource(); |
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size_t len = strlen(base->name) + 1; |
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resources[id]->name = gpr_malloc(len); |
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memcpy(resources[id]->name, base->name, len); |
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if (base->description) { |
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len = strlen(base->description) + 1; |
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resources[id]->description = gpr_malloc(len); |
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memcpy(resources[id]->description, base->description, len); |
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} |
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resources[id]->prefix = base->prefix; |
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resources[id]->n_numerators = base->n_numerators; |
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len = (size_t)base->n_numerators * sizeof(*base->numerators); |
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resources[id]->numerators = gpr_malloc(len); |
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memcpy(resources[id]->numerators, base->numerators, len); |
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resources[id]->n_denominators = base->n_denominators; |
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if (base->n_denominators != 0) { |
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len = (size_t)base->n_denominators * sizeof(*base->denominators); |
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resources[id]->denominators = gpr_malloc(len); |
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memcpy(resources[id]->denominators, base->denominators, len); |
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} |
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gpr_mu_unlock(&resource_lock); |
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return (int32_t)id; |
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}
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