1 // $Id: CQLNode.java,v 1.20 2002-12-11 17:14:20 mike Exp $
3 package org.z3950.zing.cql;
4 import java.util.Properties;
5 import java.util.Vector;
9 * Represents a node in a CQL parse-tree.
11 * @version $Id: CQLNode.java,v 1.20 2002-12-11 17:14:20 mike Exp $
13 public abstract class CQLNode {
14 CQLNode() {} // prevent javadoc from documenting this
17 * Translates a parse-tree into an XCQL document.
20 * The number of levels to indent the top element of the XCQL
21 * document. This will typically be 0 when invoked by an
22 * application; it takes higher values when this method is
23 * invoked recursively for nodes further down the tree.
25 * A String containing an XCQL document equivalent to the
26 * parse-tree whose root is this node.
28 public String toXCQL(int level) {
29 return toXCQL(level, new Vector());
32 abstract public String toXCQL(int level, Vector prefixes);
34 protected static String renderPrefixes(int level, Vector prefixes) {
35 if (prefixes.size() == 0)
37 String res = indent(level) + "<prefixes>\n";
38 for (int i = 0; i < prefixes.size(); i++) {
39 CQLPrefix p = (CQLPrefix) prefixes.get(i);
40 res += indent(level+1) + "<prefix>\n";
42 res += indent(level+2) + "<name>" + p.name + "</name>\n";
43 res += indent(level+2) +
44 "<identifier>" + p.identifier + "</identifier>\n";
45 res += indent(level+1) + "</prefix>\n";
47 return res + indent(level) + "</prefixes>\n";
51 * Decompiles a parse-tree into a CQL query.
54 * A String containing a CQL query equivalent to the parse-tree
55 * whose root is this node, so that compiling that query will
56 * yield an identical tree.
58 abstract public String toCQL();
61 * Renders a parse-tree into a Yaz-style PQF string.
62 * PQF, or Prefix Query Format, is a cryptic but powerful notation
63 * that can be trivially mapped, one-to-one, int Z39.50 Type-1 and
64 * Type-101 queries. A specification for the format can be found
66 * <A href="http://indexdata.dk/yaz/doc/tools.php#PQF"
67 * >Chapter 7 (Supporting Tools)</A> of the
68 * <A href="http://indexdata.dk/yaz/">YAZ</A> manual.
71 * A <TT>Properties</TT> object containing configuration
72 * information that specifies the mapping from CQL qualifiers,
73 * relations, etc. to Type-1 attributes. The mapping
74 * specification is described in the CQL-Java distribution's
75 * sample PQF-mapping configuration file,
76 * <TT>etc/pqf.properties</TT>, which see.
78 * A String containing a PQF query equivalent to the parse-tree
79 * whose root is this node.
81 abstract public String toPQF(Properties config)
82 throws PQFTranslationException;
85 * Returns a String of spaces for indenting to the specified level.
87 protected static String indent(int level) { return Utils.indent(level); }
90 * Returns the argument String quoted for XML.
91 * For example, each occurrence of <TT><</TT> is translated to
94 protected static String xq(String str) { return Utils.xq(str); }
97 * Renders a parser-tree into a BER-endoded packet representing an
98 * equivalent Z39.50 Type-1 query. If you don't know what that
99 * means, then you don't need this method :-) This is useful
100 * primarily for SRW-to-Z39.50 gateways.
103 * A <TT>Properties</TT> object containing configuration
104 * information that specifies the mapping from CQL qualifiers,
105 * relations, etc. to Type-1 attributes. The mapping
106 * specification is described in the CQL-Java distribution's
107 * sample PQF-mapping configuration file,
108 * <TT>etc/pqf.properties</TT>, which see.
110 * A byte array containing the BER packet.
112 * <A href="ftp://ftp.rsasecurity.com/pub/pkcs/ascii/layman.asc"
113 * >ftp://ftp.rsasecurity.com/pub/pkcs/ascii/layman.asc</A>
115 abstract public byte[] toType1BER(Properties config)
116 throws PQFTranslationException;
119 protected static final int UNIVERSAL = 0;
120 protected static final int APPLICATION = 1;
121 protected static final int CONTEXT = 2;
122 protected static final int PRIVATE = 3;
125 protected static final int PRIMITIVE = 0;
126 protected static final int CONSTRUCTED = 1;
128 // ASN.1 UNIVERSAL data types
129 public static final byte BOOLEAN = 1;
130 public static final byte INTEGER = 2;
131 public static final byte BITSTRING = 3;
132 public static final byte OCTETSTRING = 4;
133 public static final byte NULL = 5;
134 public static final byte OBJECTIDENTIFIER = 6;
135 public static final byte OBJECTDESCRIPTOR = 7;
136 public static final byte EXTERNAL = 8;
137 public static final byte ENUMERATED = 10;
138 public static final byte SEQUENCE = 16;
139 public static final byte SET = 17;
140 public static final byte VISIBLESTRING = 26;
141 public static final byte GENERALSTRING = 27;
143 protected static final int putTag(int asn1class, int fldid, int form,
144 byte[] record, int offset) {
146 record[offset++] = (byte)(fldid + asn1class*64 + form*32);
148 record[offset++] = (byte)(31 + asn1class*64 + form*32);
150 record[offset++] = (byte)(fldid);
152 record[offset++] = (byte)(128 + fldid/128);
153 record[offset++] = (byte)(fldid % 128);
160 * Put a length directly into a BER record.
162 * @param length length to put into record
163 * @return the new, incremented value of the offset parameter.
165 public // ### shouldn't this be protected?
166 static final int putLen(int len, byte[] record, int offset) {
169 record[offset++] = (byte)len;
172 record[offset] = (byte)(lenLen(len) - 1);
173 for (t = record[offset]; t > 0; t--) {
174 record[offset+t] = (byte)(len & 0xff);
178 offset += (record[offset]&0xff) + 1;
179 record[t] += 128; // turn on bit 8 in length byte.
185 * Get the length needed to represent the given length.
187 * @param length determine length needed to encode this
188 * @return length needed to encode given length
190 protected // ### shouldn't this be private?
191 static final int lenLen(int length) {
193 return ((length < 128) ? 1 :
195 (length < 65536L) ? 3 : 4);
199 * Get the length needed to represent the given number.
201 * @param number determine length needed to encode this
202 * @return length needed to encode given number
204 protected static final int numLen(long num) {
205 num = num < 0 ? -num : num;
206 // ### Wouldn't this be better done algorithmically?
207 // Or at least with the constants expressed in hex?
208 return ((num < 128) ? 1 :
210 (num < 8388608) ? 3 :
211 (num < 2147483648L) ? 4 :
212 (num < 549755813888L) ? 5 :
213 (num < 140737488355328L) ? 6 :
214 (num < 36028797018963968L) ? 7 : 8);
218 * Put a number into a given buffer
220 * @param num number to put into buffer
221 * @param record buffer to use
222 * @param offset offset into buffer
223 * @return the new, incremented value of the offset parameter.
225 protected static final int putNum(long num, byte record[], int offset) {
228 for (int count = cnt - 1; count >= 0; count--) {
229 record[offset+count] = (byte)(num & 0xff);
235 // Used only by the makeOID() method
236 private static final java.util.Hashtable madeOIDs =
237 new java.util.Hashtable(10);
239 protected static final byte[] makeOID(String oid) {
241 int dot, offset = 0, oidOffset = 0, value;
243 if ((o = (byte[])madeOIDs.get(oid)) == null) {
246 // Isn't this kind of thing excruciating in Java?
247 while (oidOffset < oid.length() &&
248 Character.isDigit(oid.charAt(oidOffset)) == true) {
249 if (offset > 90) // too large
252 dot = oid.indexOf('.', oidOffset);
256 value = Integer.parseInt(oid.substring(oidOffset, dot));
258 if (offset == 0) { // 1st two are special
259 if (dot == -1) // ### can't happen: -1 is reassigned above
260 return null; // can't be this short
261 oidOffset = dot+1; // skip past '.'
263 dot = oid.indexOf('.', oidOffset);
269 Integer.parseInt(oid.substring(oidOffset,dot));
273 o[offset++] = (byte)value;
276 byte bits[] = new byte[12]; // save a 84 (12*7) bit number
279 bits[count++] = (byte)(value & 0x7f);
283 // Now place in the correct order
285 o[offset++] = (byte)(bits[count] | 0x80);
287 o[offset++] = bits[count];
290 dot = oid.indexOf('.', oidOffset);
297 byte[] ptr = new byte[offset];
298 System.arraycopy(o, 0, ptr, 0, offset);
299 madeOIDs.put(oid, ptr);
305 public static final byte[] makeQuery(CQLNode root, Properties properties)
306 throws PQFTranslationException {
307 byte[] rpnStructure = root.toType1BER(properties);
308 byte[] qry = new byte[rpnStructure.length+100];
310 offset = putTag(CONTEXT, 1, CONSTRUCTED, qry, offset);
311 qry[offset++] = (byte)(0x80&0xff); // indefinite length
312 offset = putTag(UNIVERSAL, OBJECTIDENTIFIER, PRIMITIVE, qry, offset);
313 byte[] oid = makeOID("1.2.840.10003.3.1"); // bib-1
314 offset = putLen(oid.length, qry, offset);
315 System.arraycopy(oid, 0, qry, offset, oid.length);
316 offset += oid.length;
317 System.arraycopy(rpnStructure, 0, qry, offset, rpnStructure.length);
318 offset += rpnStructure.length;
319 qry[offset++] = 0x00; // end of query
320 qry[offset++] = 0x00;
321 byte[] q = new byte[offset];
322 System.arraycopy(qry, 0, q, 0, offset);