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author | Luca Muscariello <lumuscar+fdio@cisco.com> | 2017-02-24 07:59:45 +0000 |
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committer | Gerrit Code Review <gerrit@fd.io> | 2017-02-24 07:59:45 +0000 |
commit | e0ec678c016fbce560e7f94973d4fada3ba5e799 (patch) | |
tree | a171ed331a830510f3064a6ad99b296ac1b2d2bc /metis/ccnx/forwarder/metis/tlv/metis_TlvExtent.h | |
parent | f28308bd99381ef5f1e178e2e1f870f245e35873 (diff) | |
parent | c580a00aac271a524e5a75b35f4b91c174ed227b (diff) |
Merge "Initial commit: sb-forwarder, metis." into sb-forwarder/master
Diffstat (limited to 'metis/ccnx/forwarder/metis/tlv/metis_TlvExtent.h')
-rw-r--r-- | metis/ccnx/forwarder/metis/tlv/metis_TlvExtent.h | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/metis/ccnx/forwarder/metis/tlv/metis_TlvExtent.h b/metis/ccnx/forwarder/metis/tlv/metis_TlvExtent.h new file mode 100644 index 00000000..056ad34d --- /dev/null +++ b/metis/ccnx/forwarder/metis/tlv/metis_TlvExtent.h @@ -0,0 +1,89 @@ +/* + * Copyright (c) 2017 Cisco and/or its affiliates. + * Licensed 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 metis_TlvExtent.h + * @brief Defines the extent structure used to map a TLV packet + * + * In MetisTlvSkeleton, all the pertinent fields used by Metis are stored by their extent range in the + * received packet buffer. An extent is (offset, length). + * + */ +#ifndef Metis_metis_tlv_Extent_h +#define Metis_metis_tlv_Extent_h + +#include <stdint.h> +#include <stdbool.h> + +/** + * Stores the location of a field within a buffer. + * The values are usually in host byte order. + */ +typedef struct metis_tlv_extent { + uint16_t offset; + uint16_t length; +} MetisTlvExtent; + +/** + * Used to detect a "not found" or "not present" condition. + * Equal to { 0x0, 0x0 }, which is an invalid extent value. + */ +extern const MetisTlvExtent metisTlvExtent_NotFound; + + +/** + * Determine if two MetisTlvExtent instances are equal. + * + * The following equivalence relations on non-null `MetisTlvExtent` instances are maintained: + * + * * It is reflexive: for any non-null reference value x, `MetisTlvExtent_Equals(x, x)` + * must return true. + * + * * It is symmetric: for any non-null reference values x and y, + * `metisTlvExtent_Equals(x, y)` must return true if and only if + * `metisTlvExtent_Equals(y, x)` returns true. + * + * * It is transitive: for any non-null reference values x, y, and z, if + * `metisTlvExtent_Equals(x, y)` returns true and + * `metisTlvExtent_Equals(y, z)` returns true, + * then `metisTlvExtent_Equals(x, z)` must return true. + * + * * It is consistent: for any non-null reference values x and y, multiple + * invocations of `metisTlvExtent_Equals(x, y)` consistently return true or + * consistently return false. + * + * * For any non-null reference value x, `metisTlvExtent_Equals(x, NULL)` must + * return false. + * + * @param a A pointer to a `MetisTlvExtent` instance. + * @param b A pointer to a `MetisTlvExtent` instance. + * @return true if the two `MetisTlvExtent` instances are equal. + * + * Example: + * @code + * { + * MetisTlvExtent *a = { .offset = 5, .length = 7 }; + * MetisTlvExtent *b = { .offset = 5, .length = 8 }; + * + * if (metisTlvExtent_Equals(a, b)) { + * // true + * } else { + * // false (this is the block executed) + * } + * } + * @endcode + */ +bool metisTlvExtent_Equals(const MetisTlvExtent *a, const MetisTlvExtent *b); +#endif // Metis_metis_tlv_Extent_h |