+ * @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, new Vector());
+ }
+
+ abstract public String toXCQL(int level, Vector prefixes);
+
+ protected static String renderPrefixes(int level, Vector prefixes) {
+ if (prefixes.size() == 0)
+ return "";
+ String res = indent(level) + "
+ * @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 + * Chapter 7 (Supporting Tools) of the + * YAZ manual. + *
+ * @param config + * A Properties object containing configuration + * information that specifies the mapping from CQL qualifiers, + * relations, etc. to Type-1 attributes. The mapping + * specification is described in the CQL-Java distribution's + * sample PQF-mapping configuration file, + * etc/pqf.properties, 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 < is translated to + * <. + */ + 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 Properties object containing configuration + * information that specifies the mapping from CQL qualifiers, + * relations, etc. to Type-1 attributes. The mapping + * specification is described in the CQL-Java distribution's + * sample PQF-mapping configuration file, + * etc/pqf.properties, which see. + * @return + * A byte array containing the BER packet. + * @see + * ftp://ftp.rsasecurity.com/pub/pkcs/ascii/layman.asc + */ + 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 length 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 number 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 madeOIDs = + new java.util.Hashtable(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; + } + + 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(3)); + 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; } }