ganeshmurthy commented on a change in pull request #1452: URL: https://github.com/apache/qpid-dispatch/pull/1452#discussion_r768853507
########## File path: src/buffer_field_api.h ########## @@ -0,0 +1,311 @@ +#ifndef __dispatch_buffer_field_api_h__ +#define __dispatch_buffer_field_api_h__ 1 +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you 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. + */ + +/** @file + * Inline API for common operations on buffer_fields + * @internal + * @{ + */ + +#include "qpid/dispatch/buffer_field.h" +#include "qpid/dispatch/iterator.h" + +/* qd_buffer_field_memcpy + * + * Copy up to n octets from bfield to dest, advance bfield by the number of + * octets copied + * + * @return total of octets copied - may be < n if len(bfield) < n + */ +static inline size_t qd_buffer_field_memcpy(qd_buffer_field_t *bfield, uint8_t *dest, size_t n) +{ + const uint8_t *start = dest; + size_t count = MIN(n, bfield->length); + if (bfield->buffer) { + while (count) { + size_t avail = qd_buffer_cursor(bfield->buffer) - bfield->cursor; + if (count < avail) { + // fastpath: no need to adjust buffer pointers + memcpy(dest, bfield->cursor, count); + dest += count; + bfield->cursor += count; + bfield->length -= count; + return dest - start; + } + + // count is >= what is available in the current buffer + memcpy(dest, bfield->cursor, avail); + dest += avail; + count -= avail; + bfield->length -= avail; + bfield->cursor += avail; + if (bfield->length) { + bfield->buffer = DEQ_NEXT(bfield->buffer); + if (bfield->buffer) { + bfield->cursor = (const uint8_t *)qd_buffer_base(bfield->buffer); + } else { + // DISPATCH-1394: field is truncated (length is inaccurate!) + bfield->length = 0; + count = 0; + assert(false); // TODO(KAG): is this fixed? + } + } + } while (count); + + return dest - start; + + } else { // string/binary data + + memcpy(dest, bfield->cursor, count); + bfield->cursor += count; + bfield->length -= count; + return count; + } +} + + +/* qd_buffer_field_advance + * + * Move the cursor of bfield forward by amount octets. + * + * @return total of octets skipped - may be < amount if len(bfield) < amount + */ +static inline size_t qd_buffer_field_advance(qd_buffer_field_t *bfield, size_t amount) +{ + size_t blen = bfield->length; + size_t count = MIN(amount, blen); + if (bfield->buffer) { Review comment: Can we assume that all bfields MUST have an associated buffer. It is after all a qd_buffer_field. Don't use this data structure if you cannot associate this bfield with a buffer -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: dev-unsubscr...@qpid.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@qpid.apache.org For additional commands, e-mail: dev-h...@qpid.apache.org
