-// $Id: CQLNode.java,v 1.7 2002-10-30 09:19:26 mike Exp $
+// $Id: CQLNode.java,v 1.26 2007-07-03 13:36:03 mike Exp $
package org.z3950.zing.cql;
+import java.util.Properties;
+import java.util.Vector;
/**
* Represents a node in a CQL parse-tree.
- * ###
*
- * @version $Id: CQLNode.java,v 1.7 2002-10-30 09:19:26 mike Exp $
+ * @version $Id: CQLNode.java,v 1.26 2007-07-03 13:36:03 mike Exp $
*/
public abstract class CQLNode {
- abstract String toXCQL(int level);
- abstract String toCQL();
+ CQLNode() {} // prevent javadoc from documenting this
- protected String indent(int level) {
- String x = "";
- while (level-- > 0) {
- x += " ";
+ /**
+ * Returns the name of the result-set to which this query is a
+ * reference, if and only if the entire query consists only of a
+ * result-set reference. If it's anything else, including a
+ * boolean combination of a result-set reference with something
+ * else, then null is returned instead.
+ * @return the name of the referenced result-set
+ */
+ public String getResultSetName() {
+ return null;
+ }
+
+ /**
+ * Translates a parse-tree into an XCQL document.
+ * <P>
+ * @param level
+ * The number of levels to indent the top element of the XCQL
+ * document. This will typically be 0 when invoked by an
+ * application; it takes higher values when this method is
+ * invoked recursively for nodes further down the tree.
+ * @return
+ * A String containing an XCQL document equivalent to the
+ * parse-tree whose root is this node.
+ */
+ public String toXCQL(int level) {
+ return toXCQL(level, null);
+ }
+
+ public String toXCQL(int level, Vector<CQLPrefix> prefixes) {
+ return toXCQL(level, prefixes, null);
+ }
+
+ abstract public String toXCQL(int level, Vector<CQLPrefix> prefixes,
+ Vector<ModifierSet> sortkeys);
+
+ protected static String renderPrefixes(int level, Vector prefixes) {
+ if (prefixes == null || prefixes.size() == 0)
+ return "";
+ String res = indent(level) + "<prefixes>\n";
+ for (int i = 0; i < prefixes.size(); i++) {
+ CQLPrefix p = (CQLPrefix) prefixes.get(i);
+ res += indent(level+1) + "<prefix>\n";
+ if (p.name != null)
+ res += indent(level+2) + "<name>" + p.name + "</name>\n";
+ res += indent(level+2) +
+ "<identifier>" + p.identifier + "</identifier>\n";
+ res += indent(level+1) + "</prefix>\n";
}
- return x;
- }
-
- // XML Quote --
- // s/&/&/g;
- // s/</</g;
- // s/>/>/g;
- // This is hideously inefficient, but I just don't see a better
- // way using the standard JAVA library.
- //
- protected String xq(String str) {
- str = replace(str, "&", "&");
- str = replace(str, "<", "<");
- str = replace(str, ">", ">");
- return str;
- }
-
- // I can't _believe_ I have to write this by hand in 2002 ...
- protected static String replace(String str, String from, String to) {
- StringBuffer sb = new StringBuffer();
- int ix; // index of next `from'
- int offset = 0; // index of previous `from' + length(from)
-
- while ((ix = str.indexOf(from, offset)) != -1) {
- sb.append(str.substring(offset, ix));
- sb.append(to);
- offset = ix + from.length();
+ return res + indent(level) + "</prefixes>\n";
+ }
+
+ protected static String renderSortKeys(int level,
+ Vector<ModifierSet> sortkeys) {
+ if (sortkeys == null || sortkeys.size() == 0)
+ return "";
+ String res = indent(level) + "<sortKeys>\n";
+ for (int i = 0; i < sortkeys.size(); i++) {
+ ModifierSet key = sortkeys.get(i);
+ res += key.sortKeyToXCQL(level+1);
}
+ return res + indent(level) + "</sortKeys>\n";
+ }
+
+ /**
+ * Decompiles a parse-tree into a CQL query.
+ * <P>
+ * @return
+ * A String containing a CQL query equivalent to the parse-tree
+ * whose root is this node, so that compiling that query will
+ * yield an identical tree.
+ */
+ abstract public String toCQL();
+
+ /**
+ * Renders a parse-tree into a Yaz-style PQF string.
+ * PQF, or Prefix Query Format, is a cryptic but powerful notation
+ * that can be trivially mapped, one-to-one, int Z39.50 Type-1 and
+ * Type-101 queries. A specification for the format can be found
+ * in
+ * <A href="http://indexdata.dk/yaz/doc/tools.php#PQF"
+ * >Chapter 7 (Supporting Tools)</A> of the
+ * <A href="http://indexdata.dk/yaz/">YAZ</A> manual.
+ * <P>
+ * @param config
+ * A <TT>Properties</TT> object containing configuration
+ * information that specifies the mapping from CQL indexes,
+ * relations, etc. to Type-1 attributes. The mapping
+ * specification is described in the CQL-Java distribution's
+ * sample PQF-mapping configuration file,
+ * <TT>etc/pqf.properties</TT>, which see.
+ * @return
+ * A String containing a PQF query equivalent to the parse-tree
+ * whose root is this node.
+ */
+ abstract public String toPQF(Properties config)
+ throws PQFTranslationException;
+
+ /**
+ * Returns a String of spaces for indenting to the specified level.
+ */
+ protected static String indent(int level) { return Utils.indent(level); }
+
+ /**
+ * Returns the argument String quoted for XML.
+ * For example, each occurrence of <TT><</TT> is translated to
+ * <TT>&lt;</TT>.
+ */
+ protected static String xq(String str) { return Utils.xq(str); }
+
+ /**
+ * Renders a parser-tree into a BER-endoded packet representing an
+ * equivalent Z39.50 Type-1 query. If you don't know what that
+ * means, then you don't need this method :-) This is useful
+ * primarily for SRW-to-Z39.50 gateways.
+ *
+ * @param config
+ * A <TT>Properties</TT> object containing configuration
+ * information that specifies the mapping from CQL indexes,
+ * relations, etc. to Type-1 attributes. The mapping
+ * specification is described in the CQL-Java distribution's
+ * sample PQF-mapping configuration file,
+ * <TT>etc/pqf.properties</TT>, which see.
+ * @return
+ * A byte array containing the BER packet.
+ * @see
+ * <A href="ftp://ftp.rsasecurity.com/pub/pkcs/ascii/layman.asc"
+ * >ftp://ftp.rsasecurity.com/pub/pkcs/ascii/layman.asc</A>
+ */
+ abstract public byte[] toType1BER(Properties config)
+ throws PQFTranslationException;
+
+ // ANS.1 classes
+ protected static final int UNIVERSAL = 0;
+ protected static final int APPLICATION = 1;
+ protected static final int CONTEXT = 2;
+ protected static final int PRIVATE = 3;
+
+ // ASN.1 tag forms
+ protected static final int PRIMITIVE = 0;
+ protected static final int CONSTRUCTED = 1;
+
+ // ASN.1 UNIVERSAL data types
+ public static final byte BOOLEAN = 1;
+ public static final byte INTEGER = 2;
+ public static final byte BITSTRING = 3;
+ public static final byte OCTETSTRING = 4;
+ public static final byte NULL = 5;
+ public static final byte OBJECTIDENTIFIER = 6;
+ public static final byte OBJECTDESCRIPTOR = 7;
+ public static final byte EXTERNAL = 8;
+ public static final byte ENUMERATED = 10;
+ public static final byte SEQUENCE = 16;
+ public static final byte SET = 17;
+ public static final byte VISIBLESTRING = 26;
+ public static final byte GENERALSTRING = 27;
+
+ protected static final int putTag(int asn1class, int fldid, int form,
+ byte[] record, int offset) {
+ if (fldid < 31)
+ record[offset++] = (byte)(fldid + asn1class*64 + form*32);
+ else {
+ record[offset++] = (byte)(31 + asn1class*64 + form*32);
+ if (fldid < 128)
+ record[offset++] = (byte)(fldid);
+ else {
+ record[offset++] = (byte)(128 + fldid/128);
+ record[offset++] = (byte)(fldid % 128);
+ }
+ }
+ return offset;
+ }
+
+ /**
+ * Put a length directly into a BER record.
+ *
+ * @param len length to put into record
+ * @return the new, incremented value of the offset parameter.
+ */
+ public // ### shouldn't this be protected?
+ static final int putLen(int len, byte[] record, int offset) {
+
+ if (len < 128)
+ record[offset++] = (byte)len;
+ else {
+ int t;
+ record[offset] = (byte)(lenLen(len) - 1);
+ for (t = record[offset]; t > 0; t--) {
+ record[offset+t] = (byte)(len & 0xff);
+ len >>= 8;
+ }
+ t = offset;
+ offset += (record[offset]&0xff) + 1;
+ record[t] += 128; // turn on bit 8 in length byte.
+ }
+ return offset;
+ }
+
+ /**
+ * Get the length needed to represent the given length.
+ *
+ * @param length determine length needed to encode this
+ * @return length needed to encode given length
+ */
+ protected // ### shouldn't this be private?
+ static final int lenLen(int length) {
+
+ return ((length < 128) ? 1 :
+ (length < 256) ? 2 :
+ (length < 65536L) ? 3 : 4);
+ }
+
+ /**
+ * Get the length needed to represent the given number.
+ *
+ * @param num determine length needed to encode this
+ * @return length needed to encode given number
+ */
+ protected static final int numLen(long num) {
+ num = num < 0 ? -num : num;
+ // ### Wouldn't this be better done algorithmically?
+ // Or at least with the constants expressed in hex?
+ return ((num < 128) ? 1 :
+ (num < 32768) ? 2 :
+ (num < 8388608) ? 3 :
+ (num < 2147483648L) ? 4 :
+ (num < 549755813888L) ? 5 :
+ (num < 140737488355328L) ? 6 :
+ (num < 36028797018963968L) ? 7 : 8);
+ }
+
+ /**
+ * Put a number into a given buffer
+ *
+ * @param num number to put into buffer
+ * @param record buffer to use
+ * @param offset offset into buffer
+ * @return the new, incremented value of the offset parameter.
+ */
+ protected static final int putNum(long num, byte record[], int offset) {
+ int cnt=numLen(num);
+
+ for (int count = cnt - 1; count >= 0; count--) {
+ record[offset+count] = (byte)(num & 0xff);
+ num >>= 8;
+ }
+ return offset+cnt;
+ }
+
+ // Used only by the makeOID() method
+ private static final java.util.Hashtable<String, byte[]> madeOIDs =
+ new java.util.Hashtable<String, byte[]>(10);
+
+ protected static final byte[] makeOID(String oid) {
+ byte[] o;
+ int dot, offset = 0, oidOffset = 0, value;
+
+ if ((o = (byte[])madeOIDs.get(oid)) == null) {
+ o = new byte[100];
+
+ // Isn't this kind of thing excruciating in Java?
+ while (oidOffset < oid.length() &&
+ Character.isDigit(oid.charAt(oidOffset)) == true) {
+ if (offset > 90) // too large
+ return null;
+
+ dot = oid.indexOf('.', oidOffset);
+ if (dot == -1)
+ dot = oid.length();
+
+ value = Integer.parseInt(oid.substring(oidOffset, dot));
+
+ if (offset == 0) { // 1st two are special
+ if (dot == -1) // ### can't happen: -1 is reassigned above
+ return null; // can't be this short
+ oidOffset = dot+1; // skip past '.'
+
+ dot = oid.indexOf('.', oidOffset);
+ if (dot == -1)
+ dot = oid.length();
+
+ // ### Eh?!
+ value = value * 40 +
+ Integer.parseInt(oid.substring(oidOffset,dot));
+ }
+
+ if (value < 0x80) {
+ o[offset++] = (byte)value;
+ } else {
+ int count = 0;
+ byte bits[] = new byte[12]; // save a 84 (12*7) bit number
+
+ while (value != 0) {
+ bits[count++] = (byte)(value & 0x7f);
+ value >>= 7;
+ }
+
+ // Now place in the correct order
+ while (--count > 0)
+ o[offset++] = (byte)(bits[count] | 0x80);
+
+ o[offset++] = bits[count];
+ }
+
+ dot = oid.indexOf('.', oidOffset);
+ if (dot == -1)
+ break;
+
+ oidOffset = dot+1;
+ }
- // End of string: append last bit and we're done
- sb.append(str.substring(offset));
- return sb.toString();
+ byte[] ptr = new byte[offset];
+ System.arraycopy(o, 0, ptr, 0, offset);
+ madeOIDs.put(oid, ptr);
+ return ptr;
+ }
+ return o;
}
- // Test harness
- public static void main (String[] args) {
- CQLNode n1 = new CQLTermNode("dc.author", "=", "kernighan");
- CQLNode n2 = new CQLTermNode("dc.title", "all", "elements style");
- CQLNode root = new CQLAndNode(n1, n2);
- System.out.println(root.toXCQL(0));
+ public static final byte[] makeQuery(CQLNode root, Properties properties)
+ throws PQFTranslationException {
+ byte[] rpnStructure = root.toType1BER(properties);
+ byte[] qry = new byte[rpnStructure.length+100];
+ int offset = 0;
+ offset = putTag(CONTEXT, 1, CONSTRUCTED, qry, offset);
+ qry[offset++] = (byte)(0x80&0xff); // indefinite length
+ offset = putTag(UNIVERSAL, OBJECTIDENTIFIER, PRIMITIVE, qry, offset);
+ byte[] oid = makeOID("1.2.840.10003.3.1"); // bib-1
+ offset = putLen(oid.length, qry, offset);
+ System.arraycopy(oid, 0, qry, offset, oid.length);
+ offset += oid.length;
+ System.arraycopy(rpnStructure, 0, qry, offset, rpnStructure.length);
+ offset += rpnStructure.length;
+ qry[offset++] = 0x00; // end of query
+ qry[offset++] = 0x00;
+ byte[] q = new byte[offset];
+ System.arraycopy(qry, 0, q, 0, offset);
+ return q;
}
}
projects / cql-java-moved-to-github.git / blobdiff