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