1 // -*- mode: c++; c-basic-offset:4 -*-
2
3 // This file is part of libdap, A C++ implementation of the OPeNDAP Data
4 // Access Protocol.
5
6 // Copyright (c) 2011 OPeNDAP, Inc.
7 // Author: James Gallagher <jgallagher@opendap.org>
8 //
9 // This library is free software; you can redistribute it and/or
10 // modify it under the terms of the GNU Lesser General Public
11 // License as published by the Free Software Foundation; either
12 // version 2.1 of the License, or (at your option) any later version.
13 //
14 // This library is distributed in the hope that it will be useful,
15 // but WITHOUT ANY WARRANTY; without even the implied warranty of
16 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 // Lesser General Public License for more details.
18 //
19 // You should have received a copy of the GNU Lesser General Public
20 // License along with this library; if not, write to the Free Software
21 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 //
23 // You can contact OPeNDAP, Inc. at PO Box 112, Saunderstown, RI. 02874-0112.
24 #include "config.h"
25
26 #include <iostream>
27 #include <vector>
28
29 //#define DODS_DEBUG
30
31 #include "Keywords2.h"
32 #include "Error.h"
33 #include "escaping.h"
34 #include "debug.h"
35
36 using namespace std;
37
38 namespace libdap {
39
Keywords()40 Keywords::Keywords()
41 {
42 // Load known keywords and their allowed values
43 vector<string> v1(7);
44 v1[0] = "2"; v1[1] = "2.0"; v1[2] = "3.2"; v1[3] = "3.3"; v1[4] = "3.4";
45 v1[5] = "4"; v1[6] = "4.0";
46 value_set_t vs = value_set_t(v1.begin(), v1.end());
47 d_known_keywords["dap"] = vs;
48
49 vector<string> v2(4);
50 v2[0] = "md5"; v2[1] = "MD5"; v2[2] = "sha1"; v2[3] = "SHA1";
51 value_set_t vs2 = value_set_t(v2.begin(), v2.end());
52 d_known_keywords["checksum"] = vs2;
53 }
54
~Keywords()55 Keywords::~Keywords()
56 {
57 }
58
59 /** Static function to parse the keyword notation.
60 * @param kw the keyword clause '<word> ( <value> )'
61 * @param word (result) the word
62 * @param value (result) the value
63 * @return True if the parse was successful (word and value contain useful
64 * results) and False otherwise.
65 */
f_parse_keyword(const string & kw,string & word,string & value)66 static bool f_parse_keyword(const string &kw, string &word, string &value)
67 {
68 word = "";
69 value = "";
70 string::size_type i = kw.find('(');
71 if (i == string::npos)
72 return false;
73 word = kw.substr(0, i);
74 string::size_type j = kw.find(')');
75 if (j == string::npos)
76 return false;
77 ++i; // Move past the opening paren
78 value = kw.substr(i, j-i);
79
80 return (!word.empty() && !value.empty());
81 }
82
83 /**
84 * Add the keyword to the set of keywords that apply to this request.
85 * @note Should call m_is_valid_keyword first.
86 * @param word The keyword/function name
87 * @param value The keyword/function value
88 */
m_add_keyword(const keyword & word,const keyword_value & value)89 void Keywords::m_add_keyword(const keyword &word, const keyword_value &value)
90 {
91 d_parsed_keywords[word] = value;
92 }
93
94 /** Is the string a valid keyword clause? Assumption: the word and value have
95 * already been successfully parsed.
96 * @param word The keyword/function name
97 * @param value The keyword/function value
98 * @return True if the string is valid keyword and the value is one of the
99 * allowed values.
100 */
m_is_valid_keyword(const keyword & word,const keyword_value & value) const101 bool Keywords::m_is_valid_keyword(const keyword &word, const keyword_value &value) const
102 {
103 map<keyword, value_set_t>::const_iterator ci = d_known_keywords.find(word);
104 if (ci == d_known_keywords.end())
105 return false;
106 else {
107 value_set_t vs = ci->second;
108
109 if (vs.find(value) == vs.end())
110 throw Error("Bad value passed to the keyword/function: " + word);
111 }
112
113 return true;
114 }
115
116 /**
117 * Is the word one of the known keywords for this version of libdap?
118 * @param s As a string, including the value
119 * @return true if the keyword is known
120 */
is_known_keyword(const string & word) const121 bool Keywords::is_known_keyword(const string &word) const
122 {
123 return d_known_keywords.count(word) == 1;
124 }
125
126 /**
127 * Get a list of the strings that make up the set of current keywords for
128 * this request.
129 * @return The list of keywords as a list of string objects.
130 */
get_keywords() const131 list<Keywords::keyword> Keywords::get_keywords() const
132 {
133 list<keyword> kws;
134 map<keyword, keyword_value>::const_iterator i;
135 for (i = d_parsed_keywords.begin(); i != d_parsed_keywords.end(); ++i)
136 kws.push_front((*i).first);
137
138 return kws;
139 }
140
141
142 /**
143 * Lookup a keyword_kind and return true if it has been set for this request,
144 * otherwise return false.
145 * @param kw Keyword
146 * @return true if the keyword is set.
147 */
has_keyword(const keyword & kw) const148 bool Keywords::has_keyword(const keyword &kw) const
149 {
150 return d_parsed_keywords.count(kw) == 1;
151 }
152
153 /** Look at the parsed keywords for the value associated with a given keyword.
154 *
155 * @param k
156 * @return The value
157 */
get_keyword_value(const keyword & kw) const158 Keywords::keyword_value Keywords::get_keyword_value(const keyword &kw) const
159 {
160 if (d_known_keywords.find(kw) == d_known_keywords.end())
161 throw Error("Keyword not known (" + kw + ")");
162
163 return d_parsed_keywords.find(kw)->second;
164 }
165
166 /** Parse the constraint expression, removing all keywords. As a side effect,
167 * return the remaining CE.
168 * @param ce
169 * @return The CE stripped of all recognized keywords.
170 */
parse_keywords(const string & ce)171 string Keywords::parse_keywords(const string &ce)
172 {
173 // Get the whole CE
174 string projection = www2id(ce, "%", "%20");
175 string selection = "";
176
177 // Separate the selection part (which follows/includes the first '&')
178 string::size_type amp = projection.find('&');
179 if (amp != string::npos) {
180 selection = projection.substr(amp);
181 projection = projection.substr(0, amp);
182 }
183
184 // Extract keywords; add to the Keywords keywords. For this, scan for
185 // a known set of keywords and assume that anything else is part of the
186 // projection and should be left alone. Keywords must come before variables
187 // The 'projection' string will look like: '' or 'dap4.0' or 'dap4.0,u,v'
188 while (!projection.empty()) {
189 string::size_type i = projection.find(',');
190 string next_word = projection.substr(0, i);
191 string word, value;
192 if (f_parse_keyword(next_word, word, value)
193 && m_is_valid_keyword(word, value)) {
194 m_add_keyword(word, value);
195 if (i != string::npos)
196 projection = projection.substr(i + 1);
197 else
198 projection = "";
199 }
200 else {
201 break; // exit on first non-keyword
202 }
203 }
204
205 // The CE is whatever is left after removing the keywords
206 return projection + selection;
207 }
208
209 }
210