1/*
2 * libwebsockets - small server side websockets and web server implementation
3 *
4 * Copyright (C) 2010 - 2019 Andy Green <andy@warmcat.com>
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to
8 * deal in the Software without restriction, including without limitation the
9 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
10 * sell copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
22 * IN THE SOFTWARE.
23 */
24
25/** \defgroup search Search
26 *
27 * ##Full-text search
28 *
29 * Lws provides superfast indexing and fulltext searching from index files on
30 * storage.
31 */
32///@{
33
34struct lws_fts;
35struct lws_fts_file;
36
37/*
38 * Queries produce their results in an lwsac, using these public API types.
39 * The first thing in the lwsac is always a struct lws_fts_result (see below)
40 * containing heads for linked-lists of the other result types.
41 */
42
43/* one filepath's results */
44
45struct lws_fts_result_filepath {
46 struct lws_fts_result_filepath *next;
47 int matches; /* logical number of matches */
48 int matches_length; /* bytes in length table (may be zero) */
49 int lines_in_file;
50 int filepath_length;
51
52 /* - uint32_t line table follows (first for alignment) */
53 /* - filepath (of filepath_length) follows */
54};
55
56/* autocomplete result */
57
58struct lws_fts_result_autocomplete {
59 struct lws_fts_result_autocomplete *next;
60 int instances;
61 int agg_instances;
62 int ac_length;
63 char elided; /* children skipped in interest of antecedent children */
64 char has_children;
65
66 /* - autocomplete suggestion (of length ac_length) follows */
67};
68
69/*
70 * The results lwsac always starts with this. If no results and / or no
71 * autocomplete the members may be NULL. This implies the symbol nor any
72 * suffix on it exists in the trie file.
73 */
74struct lws_fts_result {
75 struct lws_fts_result_filepath *filepath_head;
76 struct lws_fts_result_autocomplete *autocomplete_head;
77 int duration_ms;
78 int effective_flags; /* the search flags that were used */
79};
80
81/*
82 * index creation functions
83 */
84
85/**
86 * lws_fts_create() - Create a new index file
87 *
88 * \param fd: The fd opened for write
89 *
90 * Inits a new index file, returning a struct lws_fts to represent it
91 */
92LWS_VISIBLE LWS_EXTERN struct lws_fts *
93lws_fts_create(int fd);
94
95/**
96 * lws_fts_destroy() - Finalize a new index file / destroy the trie lwsac
97 *
98 * \param trie: The previously opened index being finalized
99 *
100 * Finalizes an index file that was being created, and frees the memory involved
101 * *trie is set to NULL afterwards.
102 */
103LWS_VISIBLE LWS_EXTERN void
104lws_fts_destroy(struct lws_fts **trie);
105
106/**
107 * lws_fts_file_index() - Create a new entry in the trie file for an input path
108 *
109 * \param t: The previously opened index being written
110 * \param filepath: The filepath (which may be virtual) associated with this file
111 * \param filepath_len: The number of chars in the filepath
112 * \param priority: not used yet
113 *
114 * Returns an ordinal that represents this new filepath in the index file.
115 */
116LWS_VISIBLE LWS_EXTERN int
117lws_fts_file_index(struct lws_fts *t, const char *filepath, int filepath_len,
118 int priority);
119
120/**
121 * lws_fts_fill() - Process all or a bufferload of input file
122 *
123 * \param t: The previously opened index being written
124 * \param file_index: The ordinal representing this input filepath
125 * \param buf: A bufferload of data from the input file
126 * \param len: The number of bytes in buf
127 *
128 * Indexes a buffer of data from the input file.
129 */
130LWS_VISIBLE LWS_EXTERN int
131lws_fts_fill(struct lws_fts *t, uint32_t file_index, const char *buf,
132 size_t len);
133
134/**
135 * lws_fts_serialize() - Store the in-memory trie into the index file
136 *
137 * \param t: The previously opened index being written
138 *
139 * The trie is held in memory where it can be added to... after all the input
140 * filepaths and data have been processed, this is called to serialize /
141 * write the trie data into the index file.
142 */
143LWS_VISIBLE LWS_EXTERN int
144lws_fts_serialize(struct lws_fts *t);
145
146/*
147 * index search functions
148 */
149
150/**
151 * lws_fts_open() - Open an existing index file to search it
152 *
153 * \param filepath: The filepath to the index file to open
154 *
155 * Opening the index file returns an opaque struct lws_fts_file * that is
156 * used to perform other operations on it, or NULL if it can't be opened.
157 */
158LWS_VISIBLE LWS_EXTERN struct lws_fts_file *
159lws_fts_open(const char *filepath);
160
161#define LWSFTS_F_QUERY_AUTOCOMPLETE (1 << 0)
162#define LWSFTS_F_QUERY_FILES (1 << 1)
163#define LWSFTS_F_QUERY_FILE_LINES (1 << 2)
164#define LWSFTS_F_QUERY_QUOTE_LINE (1 << 3)
165
166struct lws_fts_search_params {
167 /* the actual search term */
168 const char *needle;
169 /* if non-NULL, FILE results for this filepath only */
170 const char *only_filepath;
171 /* will be set to the results lwsac */
172 struct lwsac *results_head;
173 /* combination of LWSFTS_F_QUERY_* flags */
174 int flags;
175 /* maximum number of autocomplete suggestions to return */
176 int max_autocomplete;
177 /* maximum number of filepaths to return */
178 int max_files;
179 /* maximum number of line number results to return per filepath */
180 int max_lines;
181};
182
183/**
184 * lws_fts_search() - Perform a search operation on an index
185 *
186 * \param jtf: The index file struct returned by lws_fts_open
187 * \param ftsp: The struct lws_fts_search_params filled in by the caller
188 *
189 * The caller should memset the ftsp struct to 0 to ensure members that may be
190 * introduced in later versions contain known values, then set the related
191 * members to describe the kind of search action required.
192 *
193 * ftsp->results_head is the results lwsac, or NULL. It should be freed with
194 * lwsac_free() when the results are finished with.
195 *
196 * Returns a pointer into the results lwsac that is a struct lws_fts_result
197 * containing the head pointers into linked-lists of results for autocomplete
198 * and filepath data, along with some sundry information. This does not need
199 * to be freed since freeing the lwsac will also remove this and everything it
200 * points to.
201 */
202LWS_VISIBLE LWS_EXTERN struct lws_fts_result *
203lws_fts_search(struct lws_fts_file *jtf, struct lws_fts_search_params *ftsp);
204
205/**
206 * lws_fts_close() - Close a previously-opened index file
207 *
208 * \param jtf: The pointer returned from the open
209 *
210 * Closes the file handle on the index and frees any allocations
211 */
212LWS_VISIBLE LWS_EXTERN void
213lws_fts_close(struct lws_fts_file *jtf);
214
215///@}
216