jdk/make/src/classes/build/tools/generatecharacter/Utility.java
changeset 21805 c7d7946239de
parent 5506 202f599c92aa
child 23010 6dadb192ad81
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/make/src/classes/build/tools/generatecharacter/Utility.java	Thu Nov 14 11:19:32 2013 +0100
@@ -0,0 +1,407 @@
+/*
+ * Copyright (c) 2002, 2003, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package build.tools.generatecharacter;
+
+import java.text.*;
+import java.util.*;
+
+public class Utility {
+    static byte peekByte(String s, int index) {
+        char c = s.charAt(index/2);
+        return ((index&1)==0)?(byte)(c>>8):(byte)c;
+    }
+
+    static short peekShort(String s, int index) {
+        return (short)s.charAt(index);
+    }
+
+    static int peekInt(String s, int index) {
+        index *= 2;
+        return (((int)s.charAt(index)) << 16) | s.charAt(index+1);
+    }
+
+    static void poke(String s, int index, byte value) {
+        int mask = 0xFF00;
+        int ivalue = value;
+        if ((index&1)==0) {
+            ivalue <<= 8;
+            mask = 0x00FF;
+        }
+        index /= 2;
+        if (index == s.length()) {
+            s = s + (char)ivalue;
+        }
+        else if (index == 0) {
+            s = (char)(ivalue|(s.charAt(0)&mask)) + s.substring(1);
+        }
+        else {
+            s = s.substring(0, index) + (char)(ivalue|(s.charAt(index)&mask))
+                + s.substring(index+1);
+        }
+    }
+
+    static void poke(String s, int index, short value) {
+        if (index == s.length()) {
+            s = s + (char)value;
+        }
+        else if (index == 0) {
+            s = (char)value + s.substring(1);
+        }
+        else {
+            s = s.substring(0, index) + (char)value + s.substring(index+1);
+        }
+    }
+
+    static void poke(String s, int index, int value) {
+        index *= 2;
+        char hi = (char)(value >> 16);
+        if (index == s.length()) {
+            s = s + hi + (char)value;
+        }
+        else if (index == 0) {
+            s = hi + (char)value + s.substring(2);
+        }
+        else {
+            s = s.substring(0, index) + hi + (char)value + s.substring(index+2);
+        }
+    }
+
+    /**
+     * The ESCAPE character is used during run-length encoding.  It signals
+     * a run of identical chars.
+     */
+    static final char ESCAPE = '\uA5A5';
+
+    /**
+     * The ESCAPE_BYTE character is used during run-length encoding.  It signals
+     * a run of identical bytes.
+     */
+    static final byte ESCAPE_BYTE = (byte)0xA5;
+
+    /**
+     * Construct a string representing a short array.  Use run-length encoding.
+     * A character represents itself, unless it is the ESCAPE character.  Then
+     * the following notations are possible:
+     *   ESCAPE ESCAPE   ESCAPE literal
+     *   ESCAPE n c      n instances of character c
+     * Since an encoded run occupies 3 characters, we only encode runs of 4 or
+     * more characters.  Thus we have n > 0 and n != ESCAPE and n <= 0xFFFF.
+     * If we encounter a run where n == ESCAPE, we represent this as:
+     *   c ESCAPE n-1 c
+     * The ESCAPE value is chosen so as not to collide with commonly
+     * seen values.
+     */
+    static final String arrayToRLEString(short[] a) {
+        StringBuffer buffer = new StringBuffer();
+        // for (int i=0; i<a.length; ++i) buffer.append((char) a[i]);
+        buffer.append((char) (a.length >> 16));
+        buffer.append((char) a.length);
+        short runValue = a[0];
+        int runLength = 1;
+        for (int i=1; i<a.length; ++i) {
+            short s = a[i];
+            if (s == runValue && runLength < 0xFFFF) ++runLength;
+            else {
+                encodeRun(buffer, runValue, runLength);
+                runValue = s;
+                runLength = 1;
+            }
+        }
+        encodeRun(buffer, runValue, runLength);
+        return buffer.toString();
+    }
+
+    /**
+     * Construct a string representing a byte array.  Use run-length encoding.
+     * Two bytes are packed into a single char, with a single extra zero byte at
+     * the end if needed.  A byte represents itself, unless it is the
+     * ESCAPE_BYTE.  Then the following notations are possible:
+     *   ESCAPE_BYTE ESCAPE_BYTE   ESCAPE_BYTE literal
+     *   ESCAPE_BYTE n b           n instances of byte b
+     * Since an encoded run occupies 3 bytes, we only encode runs of 4 or
+     * more bytes.  Thus we have n > 0 and n != ESCAPE_BYTE and n <= 0xFF.
+     * If we encounter a run where n == ESCAPE_BYTE, we represent this as:
+     *   b ESCAPE_BYTE n-1 b
+     * The ESCAPE_BYTE value is chosen so as not to collide with commonly
+     * seen values.
+     */
+    static final String arrayToRLEString(byte[] a) {
+        StringBuffer buffer = new StringBuffer();
+        buffer.append((char) (a.length >> 16));
+        buffer.append((char) a.length);
+        byte runValue = a[0];
+        int runLength = 1;
+        byte[] state = new byte[2];
+        for (int i=1; i<a.length; ++i) {
+            byte b = a[i];
+            if (b == runValue && runLength < 0xFF) ++runLength;
+            else {
+                encodeRun(buffer, runValue, runLength, state);
+                runValue = b;
+                runLength = 1;
+            }
+        }
+        encodeRun(buffer, runValue, runLength, state);
+
+        // We must save the final byte, if there is one, by padding
+        // an extra zero.
+        if (state[0] != 0) appendEncodedByte(buffer, (byte)0, state);
+
+        return buffer.toString();
+    }
+
+    /**
+     * Encode a run, possibly a degenerate run (of < 4 values).
+     * @param length The length of the run; must be > 0 && <= 0xFFFF.
+     */
+    private static final void encodeRun(StringBuffer buffer, short value, int length) {
+        if (length < 4) {
+            for (int j=0; j<length; ++j) {
+                if (value == (int) ESCAPE) buffer.append(ESCAPE);
+                buffer.append((char) value);
+            }
+        }
+        else {
+            if (length == (int) ESCAPE) {
+                if (value == (int) ESCAPE) buffer.append(ESCAPE);
+                buffer.append((char) value);
+                --length;
+            }
+            buffer.append(ESCAPE);
+            buffer.append((char) length);
+            buffer.append((char) value); // Don't need to escape this value
+        }
+    }
+
+    /**
+     * Encode a run, possibly a degenerate run (of < 4 values).
+     * @param length The length of the run; must be > 0 && <= 0xFF.
+     */
+    private static final void encodeRun(StringBuffer buffer, byte value, int length,
+                                        byte[] state) {
+        if (length < 4) {
+            for (int j=0; j<length; ++j) {
+                if (value == ESCAPE_BYTE) appendEncodedByte(buffer, ESCAPE_BYTE, state);
+                appendEncodedByte(buffer, value, state);
+            }
+        }
+        else {
+            if (length == ESCAPE_BYTE) {
+                if (value == ESCAPE_BYTE) appendEncodedByte(buffer, ESCAPE_BYTE, state);
+                appendEncodedByte(buffer, value, state);
+                --length;
+            }
+            appendEncodedByte(buffer, ESCAPE_BYTE, state);
+            appendEncodedByte(buffer, (byte)length, state);
+            appendEncodedByte(buffer, value, state); // Don't need to escape this value
+        }
+    }
+
+    /**
+     * Append a byte to the given StringBuffer, packing two bytes into each
+     * character.  The state parameter maintains intermediary data between
+     * calls.
+     * @param state A two-element array, with state[0] == 0 if this is the
+     * first byte of a pair, or state[0] != 0 if this is the second byte
+     * of a pair, in which case state[1] is the first byte.
+     */
+    private static final void appendEncodedByte(StringBuffer buffer, byte value,
+                                                byte[] state) {
+        if (state[0] != 0) {
+            char c = (char) ((state[1] << 8) | (((int) value) & 0xFF));
+            buffer.append(c);
+            state[0] = 0;
+        }
+        else {
+            state[0] = 1;
+            state[1] = value;
+        }
+    }
+
+    /**
+     * Construct an array of shorts from a run-length encoded string.
+     */
+    static final short[] RLEStringToShortArray(String s) {
+        int length = (((int) s.charAt(0)) << 16) | ((int) s.charAt(1));
+        short[] array = new short[length];
+        int ai = 0;
+        for (int i=2; i<s.length(); ++i) {
+            char c = s.charAt(i);
+            if (c == ESCAPE) {
+                c = s.charAt(++i);
+                if (c == ESCAPE) array[ai++] = (short) c;
+                else {
+                    int runLength = (int) c;
+                    short runValue = (short) s.charAt(++i);
+                    for (int j=0; j<runLength; ++j) array[ai++] = runValue;
+                }
+            }
+            else {
+                array[ai++] = (short) c;
+            }
+        }
+
+        if (ai != length)
+            throw new InternalError("Bad run-length encoded short array");
+
+        return array;
+    }
+
+    /**
+     * Construct an array of bytes from a run-length encoded string.
+     */
+    static final byte[] RLEStringToByteArray(String s) {
+        int length = (((int) s.charAt(0)) << 16) | ((int) s.charAt(1));
+        byte[] array = new byte[length];
+        boolean nextChar = true;
+        char c = 0;
+        int node = 0;
+        int runLength = 0;
+        int i = 2;
+        for (int ai=0; ai<length; ) {
+            // This part of the loop places the next byte into the local
+            // variable 'b' each time through the loop.  It keeps the
+            // current character in 'c' and uses the boolean 'nextChar'
+            // to see if we've taken both bytes out of 'c' yet.
+            byte b;
+            if (nextChar) {
+                c = s.charAt(i++);
+                b = (byte) (c >> 8);
+                nextChar = false;
+            }
+            else {
+                b = (byte) (c & 0xFF);
+                nextChar = true;
+            }
+
+            // This part of the loop is a tiny state machine which handles
+            // the parsing of the run-length encoding.  This would be simpler
+            // if we could look ahead, but we can't, so we use 'node' to
+            // move between three nodes in the state machine.
+            switch (node) {
+            case 0:
+                // Normal idle node
+                if (b == ESCAPE_BYTE) {
+                    node = 1;
+                }
+                else {
+                    array[ai++] = b;
+                }
+                break;
+            case 1:
+                // We have seen one ESCAPE_BYTE; we expect either a second
+                // one, or a run length and value.
+                if (b == ESCAPE_BYTE) {
+                    array[ai++] = ESCAPE_BYTE;
+                    node = 0;
+                }
+                else {
+                    runLength = b;
+                    // Interpret signed byte as unsigned
+                    if (runLength < 0) runLength += 0x100;
+                    node = 2;
+                }
+                break;
+            case 2:
+                // We have seen an ESCAPE_BYTE and length byte.  We interpret
+                // the next byte as the value to be repeated.
+                for (int j=0; j<runLength; ++j) array[ai++] = b;
+                node = 0;
+                break;
+            }
+        }
+
+        if (node != 0)
+            throw new InternalError("Bad run-length encoded byte array");
+
+        if (i != s.length())
+            throw new InternalError("Excess data in RLE byte array string");
+
+        return array;
+    }
+
+    /**
+     * Format a String for representation in a source file.  This includes
+     * breaking it into lines escaping characters using octal notation
+     * when necessary (control characters and double quotes).
+     */
+    static final String formatForSource(String s) {
+        return formatForSource(s, "        ");
+    }
+
+    /**
+     * Format a String for representation in a source file.  This includes
+     * breaking it into lines escaping characters using octal notation
+     * when necessary (control characters and double quotes).
+     */
+    static final String formatForSource(String s, String indent) {
+        StringBuffer buffer = new StringBuffer();
+        for (int i=0; i<s.length();) {
+            if (i > 0) buffer.append("+\n");
+            int limit = buffer.length() + 78; // Leave 2 for trailing <"+>
+            buffer.append(indent + '"');
+            while (i<s.length() && buffer.length()<limit) {
+                char c = s.charAt(i++);
+                /* This works too but it's kind of unnecessary; might as
+                   well keep things simple.
+                if (c == '\\' || c == '"') {
+                    // Escape backslash and double-quote.  Don't need to
+                    // escape single-quote.
+                    buffer.append("\\" + c);
+                }
+                else if (c >= '\u0020' && c <= '\u007E') {
+                    // Printable ASCII ranges from ' ' to '~'
+                    buffer.append(c);
+                }
+                else
+                */
+                if (c <= '\377') {
+                    // Represent control characters
+                    // using octal notation; otherwise the string we form
+                    // won't compile, since Unicode escape sequences are
+                    // processed before tokenization.
+                    buffer.append('\\');
+                    buffer.append(HEX_DIGIT[(c & 0700) >> 6]); // HEX_DIGIT works for octal
+                    buffer.append(HEX_DIGIT[(c & 0070) >> 3]);
+                    buffer.append(HEX_DIGIT[(c & 0007)]);
+                }
+                else {
+                    // Handle the rest with Unicode
+                    buffer.append("\\u");
+                    buffer.append(HEX_DIGIT[(c & 0xF000) >> 12]);
+                    buffer.append(HEX_DIGIT[(c & 0x0F00) >> 8]);
+                    buffer.append(HEX_DIGIT[(c & 0x00F0) >> 4]);
+                    buffer.append(HEX_DIGIT[(c & 0x000F)]);
+                }
+            }
+            buffer.append('"');
+        }
+        return buffer.toString();
+    }
+
+    static final char[] HEX_DIGIT = {'0','1','2','3','4','5','6','7',
+                                     '8','9','A','B','C','D','E','F'};
+}