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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-10 20:34:10 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-10 20:34:10 +0000 |
commit | e4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc (patch) | |
tree | 68cb5ef9081156392f1dd62a00c6ccc1451b93df /wsutil/wmem/wmem_multimap.h | |
parent | Initial commit. (diff) | |
download | wireshark-e4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc.tar.xz wireshark-e4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc.zip |
Adding upstream version 4.2.2.upstream/4.2.2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | wsutil/wmem/wmem_multimap.h | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/wsutil/wmem/wmem_multimap.h b/wsutil/wmem/wmem_multimap.h new file mode 100644 index 0000000..57f0fef --- /dev/null +++ b/wsutil/wmem/wmem_multimap.h @@ -0,0 +1,195 @@ +/** @file + * + * Definitions for the Wireshark Memory Manager Hash Multimap + * Copyright 2021, John Thacker <johnthacker@gmail.com> + * Copyright 2014, Evan Huus <eapache@gmail.com> + * + * Wireshark - Network traffic analyzer + * By Gerald Combs <gerald@wireshark.org> + * Copyright 1998 Gerald Combs + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#ifndef __WMEM_MULTIMAP_H__ +#define __WMEM_MULTIMAP_H__ + +#include <glib.h> + +#include "wmem_core.h" +#include "wmem_list.h" + +#ifdef __cplusplus +extern "C" { +#endif /* __cplusplus */ + +/** @addtogroup wmem + * @{ + * @defgroup wmem-multimap Hash Multimap + * + * A hash multimap implementation on top of wmem_map and wmem_tree, storing + * multiple values at each hash key in a tree indexed by a 32 bit integer. + * + * The primary use case is a protocol with an ID used as the hash lookup + * key that can be reused in a capture, and the frame number used as the + * tree key. We often want to find the most recent frame that had a certain + * ID, e.g. for request/response matching, and wmem_multimap_lookup32_le() + * serves that purpose. + * + * Since the tree implementation is a self-balancing red-black tree, lookup + * time is still O(log(n)) even though elements with equivalent hash keys + * are usually added in increasing order of frame number. + * + * NOTE: The multimap does not yet support inserting items without + * specifying the tree key, because the total capacity of individual trees + * (including deleted nodes) is not tracked. + * + * @{ + */ + +typedef struct _wmem_multimap_t wmem_multimap_t; + +/** Creates a multimap with the given allocator scope. When the scope is emptied, + * the map is fully destroyed. Items stored in it will not be freed unless they + * were allocated from the same scope. + * + * @param allocator The allocator scope with which to create the map. + * @param hash_func The hash function used to place inserted keys. + * @param eql_func The equality function used to compare inserted keys. + * @return The newly-allocated map. + */ +WS_DLL_PUBLIC +wmem_multimap_t * +wmem_multimap_new(wmem_allocator_t *allocator, + GHashFunc hash_func, GEqualFunc eql_func) +G_GNUC_MALLOC; + +/** Creates a multimap with two allocator scopes. The base structure lives in the + * metadata scope, and the map data lives in the data scope. Every time free_all + * occurs in the data scope the map is transparently emptied without affecting + * the location of the base / metadata structure. + * + * WARNING: None of the map (even the part in the metadata scope) can be used + * after the data scope has been *destroyed*. + * + * The primary use for this function is to create maps that reset for each new + * capture file that is loaded. This can be done by specifying wmem_epan_scope() + * as the metadata scope and wmem_file_scope() as the data scope. + */ +WS_DLL_PUBLIC +wmem_multimap_t * +wmem_multimap_new_autoreset(wmem_allocator_t *metadata_scope, wmem_allocator_t *data_scope, + GHashFunc hash_func, GEqualFunc eql_func) +G_GNUC_MALLOC; + +/** Retrieves a list of the keys inside the multimap + * + * @param list_allocator The allocator scope for the returned list. + * @param map The multimap to extract keys from + * @return list of keys in the multimap + */ +WS_DLL_PUBLIC +wmem_list_t* +wmem_multimap_get_keys(wmem_allocator_t *list_allocator, wmem_multimap_t *map); + +/** Return the total number of elements in the multimap. + * + * @param map The multimap to use + * @return the number of elements +*/ +WS_DLL_PUBLIC +unsigned +wmem_multimap_size(wmem_multimap_t *map); + +/** Returns the number of values in the multimap with a certain hash key. + * (Note: This is the number of current elements, so this can only be used to + * safely generate unique tree keys prior to insertion if no values have been + * removed, due to how the tree implementation works.) + * + * @param map The multimap to search in. + * @param key The primary key to lookup in the map. + * @return The number of values in the tree stored at map key, or zero if no + * tree exists at that key. + */ +WS_DLL_PUBLIC +unsigned +wmem_multimap_count(wmem_multimap_t *map, const void *key); + +/** Insert a value in the multimap. + * + * @param map The multimap to insert into. + * @param key The key to insert by in the map. + * @param frame_num The key to insert by in the tree. + * @param value The value to insert. + * @return true if there was already a tree mapped at key, in which case the + * caller may safely free key. (This is not necessary if key is allocated with + * a wmem pool.) + * + * Note: as with wmem_tree, if there is already a node with the same pair + * of keys, then the existing value will simply be overwritten. This is not + * a problem if the value is wmem allocated, but if it is manually managed, + * then you must ensure that the pair is unique or do a lookup before inserting. + */ +WS_DLL_PUBLIC +bool +wmem_multimap_insert32(wmem_multimap_t *map, const void *key, uint32_t frame_num, void *value); + +/** Lookup a value in the multimap combination with an exact match. + * + * @param map The multimap to search in. + * @param key The primary key to lookup in the map. + * @param frame_num The secondary key to lookup in the tree. + * @return The value stored at the keys if any, or NULL. + */ +WS_DLL_PUBLIC +void * +wmem_multimap_lookup32(wmem_multimap_t *map, const void *key, const uint32_t frame_num); + +/** Lookup a value in the multimap with an exact match for the map key + * and the largest value less than or equal to the tree key. This is + * useful for request/response matching where IDs can be reused. + * + * @param map The multimap to search in. + * @param key The primary key to lookup in the map. + * @param frame_num The secondary key to lookup in the tree. + * @return The value stored at the primary key in the map and with the largest + * key in the tree that is less than or equal to the second key if any, or NULL. + */ +WS_DLL_PUBLIC +void * +wmem_multimap_lookup32_le(wmem_multimap_t *map, const void *key, const uint32_t frame_num); + +/** Remove a value from the multimap. If no value is stored at that key pair, + * nothing happens. As with wmem_tree, this is not really a remove, but the + * value is set to NULL so that wmem_multimap_lookup32 not will find it. + * + * @param map The multimap to remove from. + * @param key The map key of the value to remove. + * @param frame_num The tree key of the value to remove. + * @return The (removed) value stored at the key if any, or NULL. + */ +WS_DLL_PUBLIC +void * +wmem_multimap_remove32(wmem_multimap_t *map, const void *key, const uint32_t frame_num); + +/** @} + * @} */ + +#ifdef __cplusplus +} +#endif /* __cplusplus */ + +#endif /* __WMEM_MULTIMAP_H__ */ + +/* + * Editor modelines - https://www.wireshark.org/tools/modelines.html + * + * Local variables: + * c-basic-offset: 4 + * tab-width: 8 + * indent-tabs-mode: nil + * End: + * + * vi: set shiftwidth=4 tabstop=8 expandtab: + * :indentSize=4:tabSize=8:noTabs=true: + */ |