108 lines
2.5 KiB
C
108 lines
2.5 KiB
C
#ifndef AD3_TERNARYTRIE
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#define AD3_TERNARYTRIE
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/**
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* The implementation of a Ternary Trie.
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*
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* Each node should be represented by a binary tree in order to reduce the memory usage.
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*/
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#include <stdbool.h>
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#include <stddef.h>
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static const char charset[] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
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static const size_t charset_len = sizeof(charset) - 1;
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// Length of randomly generated keys
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#define RANDOM_KEY_LENGTH 4
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/**
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* Type definition for the struct representing the current Trie.
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*
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* You can (and should) redefine this in your c-file with the concrete fields.
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*/
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typedef struct ttrie TernaryTrie;
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typedef enum entry_type {
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Redirect,
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Paste,
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Unknown
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} EntryType;
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typedef struct entry {
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EntryType type;
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char *string;
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} Entry;
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Entry *entry_new(EntryType type, const char *string);
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/**
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* Allocate and initialize an empty Trie.
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*
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* @return a pointer to an empty Trie struct
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*/
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TernaryTrie* ternarytrie_init();
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/**
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* Populate trie with entries stored in the given file.
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*
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* @param trie
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* @param file_path path to file containing entries
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* @return amount of entries added; -1 if an error occured
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*/
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int ternarytrie_populate(TernaryTrie* trie, const char* file_path);
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/**
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* De-allocate a trie by freeing the memory occupied by this trie.
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*
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* @param trie which should be freed
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*/
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void ternarytrie_free(TernaryTrie* trie);
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/**
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* Search for an entry in the trie.
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*
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* @param trie
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* @param key key representing the entry
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* @return pointer to entry; NULL if not found
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*/
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Entry *ternarytrie_search(TernaryTrie* trie, const char* key);
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/**
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* Add a string to this trie.
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*
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* @param trie
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* @param key key to represent entry with
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* @param entry entry to add
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* @return true if the trie was changed by this operation, false if it was already present
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*/
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bool ternarytrie_add(TernaryTrie* trie, const char* key, Entry *entry);
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/**
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* Add an entry by generating a random string as the key.
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*
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* @param trie
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* @param entry entry to add
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* @return the generated key
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*/
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char *ternarytrie_add_random(TernaryTrie *trie, Entry *entry);
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/**
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* Remove an entry from this trie given its key.
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*
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* @param trie
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* @param key key representing entry
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* @return true if the entry was present and has been removed, false if it was not present
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*/
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bool ternarytrie_remove(TernaryTrie* trie, const char *key);
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/**
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* Returns the number of entries in this trie.
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*
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* @param trie
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* @return the number of entries in this trie
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*/
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size_t ternarytrie_size(TernaryTrie* trie);
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#endif //AD3_TERNARYTRIE
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