From f55750d05a04484b719220f21e34c05017f001fd Mon Sep 17 00:00:00 2001 From: Brian Doherty Date: Thu, 17 May 2012 10:06:19 -0700 Subject: [PATCH] 6924259: Remove offset and count fields from java.lang.String Removes the use of shared character array buffers by String along with the two fields needed to support the use of shared buffers. Reviewed-by: alanb, mduigou, forax, briangoetz --- jdk/src/share/classes/java/lang/Integer.java | 2 +- jdk/src/share/classes/java/lang/Long.java | 2 +- jdk/src/share/classes/java/lang/String.java | 522 ++++++++---------- .../share/classes/java/lang/StringCoding.java | 2 + 4 files changed, 237 insertions(+), 291 deletions(-) diff --git a/jdk/src/share/classes/java/lang/Integer.java b/jdk/src/share/classes/java/lang/Integer.java index c33e90a5e49..48ef1bbbbfb 100644 --- a/jdk/src/share/classes/java/lang/Integer.java +++ b/jdk/src/share/classes/java/lang/Integer.java @@ -381,7 +381,7 @@ public final class Integer extends Number implements Comparable { int size = (i < 0) ? stringSize(-i) + 1 : stringSize(i); char[] buf = new char[size]; getChars(i, size, buf); - return new String(0, size, buf); + return new String(buf, true); } /** diff --git a/jdk/src/share/classes/java/lang/Long.java b/jdk/src/share/classes/java/lang/Long.java index f4dc32dcdff..55f7b1a7e9d 100644 --- a/jdk/src/share/classes/java/lang/Long.java +++ b/jdk/src/share/classes/java/lang/Long.java @@ -373,7 +373,7 @@ public final class Long extends Number implements Comparable { int size = (i < 0) ? stringSize(-i) + 1 : stringSize(i); char[] buf = new char[size]; getChars(i, size, buf); - return new String(0, size, buf); + return new String(buf, true); } /** diff --git a/jdk/src/share/classes/java/lang/String.java b/jdk/src/share/classes/java/lang/String.java index 79c71d119a5..8d50ded89a9 100644 --- a/jdk/src/share/classes/java/lang/String.java +++ b/jdk/src/share/classes/java/lang/String.java @@ -108,17 +108,10 @@ import java.util.regex.PatternSyntaxException; */ public final class String - implements java.io.Serializable, Comparable, CharSequence -{ + implements java.io.Serializable, Comparable, CharSequence { /** The value is used for character storage. */ private final char value[]; - /** The offset is the first index of the storage that is used. */ - private final int offset; - - /** The count is the number of characters in the String. */ - private final int count; - /** Cache the hash code for the string */ private int hash; // Default to 0 @@ -138,7 +131,7 @@ public final class String * string instance within the stream. */ private static final ObjectStreamField[] serialPersistentFields = - new ObjectStreamField[0]; + new ObjectStreamField[0]; /** * Initializes a newly created {@code String} object so that it represents @@ -146,8 +139,6 @@ public final class String * unnecessary since Strings are immutable. */ public String() { - this.offset = 0; - this.count = 0; this.value = new char[0]; } @@ -162,23 +153,8 @@ public final class String * A {@code String} */ public String(String original) { - int size = original.count; - char[] originalValue = original.value; - char[] v; - if (originalValue.length > size) { - // The array representing the String is bigger than the new - // String itself. Perhaps this constructor is being called - // in order to trim the baggage, so make a copy of the array. - int off = original.offset; - v = Arrays.copyOfRange(originalValue, off, off+size); - } else { - // The array representing the String is the same - // size as the String, so no point in making a copy. - v = originalValue; - } - this.offset = 0; - this.count = size; - this.value = v; + this.value = original.value; + this.hash = original.hash; } /** @@ -191,10 +167,7 @@ public final class String * The initial value of the string */ public String(char value[]) { - int size = value.length; - this.offset = 0; - this.count = size; - this.value = Arrays.copyOf(value, size); + this.value = Arrays.copyOf(value, value.length); } /** @@ -229,8 +202,6 @@ public final class String if (offset > value.length - count) { throw new StringIndexOutOfBoundsException(offset + count); } - this.offset = 0; - this.count = count; this.value = Arrays.copyOfRange(value, offset, offset+count); } @@ -293,14 +264,12 @@ public final class String for (int i = offset, j = 0; i < end; i++, j++) { int c = codePoints[i]; if (Character.isBmpCodePoint(c)) - v[j] = (char) c; + v[j] = (char)c; else Character.toSurrogates(c, v, j++); } - this.value = v; - this.count = n; - this.offset = 0; + this.value = v; } /** @@ -348,17 +317,15 @@ public final class String char value[] = new char[count]; if (hibyte == 0) { - for (int i = count ; i-- > 0 ;) { - value[i] = (char) (ascii[i + offset] & 0xff); + for (int i = count; i-- > 0;) { + value[i] = (char)(ascii[i + offset] & 0xff); } } else { hibyte <<= 8; - for (int i = count ; i-- > 0 ;) { - value[i] = (char) (hibyte | (ascii[i + offset] & 0xff)); + for (int i = count; i-- > 0;) { + value[i] = (char)(hibyte | (ascii[i + offset] & 0xff)); } } - this.offset = 0; - this.count = count; this.value = value; } @@ -444,15 +411,11 @@ public final class String * @since JDK1.1 */ public String(byte bytes[], int offset, int length, String charsetName) - throws UnsupportedEncodingException - { + throws UnsupportedEncodingException { if (charsetName == null) throw new NullPointerException("charsetName"); checkBounds(bytes, offset, length); - char[] v = StringCoding.decode(charsetName, bytes, offset, length); - this.offset = 0; - this.count = v.length; - this.value = v; + this.value = StringCoding.decode(charsetName, bytes, offset, length); } /** @@ -489,10 +452,7 @@ public final class String if (charset == null) throw new NullPointerException("charset"); checkBounds(bytes, offset, length); - char[] v = StringCoding.decode(charset, bytes, offset, length); - this.offset = 0; - this.count = v.length; - this.value = v; + this.value = StringCoding.decode(charset, bytes, offset, length); } /** @@ -519,8 +479,7 @@ public final class String * @since JDK1.1 */ public String(byte bytes[], String charsetName) - throws UnsupportedEncodingException - { + throws UnsupportedEncodingException { this(bytes, 0, bytes.length, charsetName); } @@ -576,10 +535,7 @@ public final class String */ public String(byte bytes[], int offset, int length) { checkBounds(bytes, offset, length); - char[] v = StringCoding.decode(bytes, offset, length); - this.offset = 0; - this.count = v.length; - this.value = v; + this.value = StringCoding.decode(bytes, offset, length); } /** @@ -612,10 +568,9 @@ public final class String * A {@code StringBuffer} */ public String(StringBuffer buffer) { - String result = buffer.toString(); - this.value = result.value; - this.count = result.count; - this.offset = result.offset; + synchronized(buffer) { + this.value = Arrays.copyOf(buffer.getValue(), buffer.length()); + } } /** @@ -634,18 +589,18 @@ public final class String * @since 1.5 */ public String(StringBuilder builder) { - String result = builder.toString(); - this.value = result.value; - this.count = result.count; - this.offset = result.offset; + this.value = Arrays.copyOf(builder.getValue(), builder.length()); } - - // Package private constructor which shares value array for speed. - String(int offset, int count, char value[]) { + /* + * Package private constructor which shares value array for speed. + * this constructor is always expected to be called with share==true. + * a separate constructor is needed because we already have a public + * String(char[]) constructor that makes a copy of the given char[]. + */ + String(char[] value, boolean share) { + // assert share : "unshared not supported"; this.value = value; - this.offset = offset; - this.count = count; } /** @@ -657,7 +612,7 @@ public final class String * object. */ public int length() { - return count; + return value.length; } /** @@ -669,7 +624,7 @@ public final class String * @since 1.6 */ public boolean isEmpty() { - return count == 0; + return value.length == 0; } /** @@ -691,10 +646,10 @@ public final class String * string. */ public char charAt(int index) { - if ((index < 0) || (index >= count)) { + if ((index < 0) || (index >= value.length)) { throw new StringIndexOutOfBoundsException(index); } - return value[index + offset]; + return value[index]; } /** @@ -720,10 +675,10 @@ public final class String * @since 1.5 */ public int codePointAt(int index) { - if ((index < 0) || (index >= count)) { + if ((index < 0) || (index >= value.length)) { throw new StringIndexOutOfBoundsException(index); } - return Character.codePointAtImpl(value, offset + index, offset + count); + return Character.codePointAtImpl(value, index, value.length); } /** @@ -750,10 +705,10 @@ public final class String */ public int codePointBefore(int index) { int i = index - 1; - if ((i < 0) || (i >= count)) { + if ((i < 0) || (i >= value.length)) { throw new StringIndexOutOfBoundsException(index); } - return Character.codePointBeforeImpl(value, offset + index, offset); + return Character.codePointBeforeImpl(value, index, 0); } /** @@ -778,10 +733,10 @@ public final class String * @since 1.5 */ public int codePointCount(int beginIndex, int endIndex) { - if (beginIndex < 0 || endIndex > count || beginIndex > endIndex) { + if (beginIndex < 0 || endIndex > value.length || beginIndex > endIndex) { throw new IndexOutOfBoundsException(); } - return Character.codePointCountImpl(value, offset+beginIndex, endIndex-beginIndex); + return Character.codePointCountImpl(value, beginIndex, endIndex - beginIndex); } /** @@ -805,11 +760,11 @@ public final class String * @since 1.5 */ public int offsetByCodePoints(int index, int codePointOffset) { - if (index < 0 || index > count) { + if (index < 0 || index > value.length) { throw new IndexOutOfBoundsException(); } - return Character.offsetByCodePointsImpl(value, offset, count, - offset+index, codePointOffset) - offset; + return Character.offsetByCodePointsImpl(value, 0, value.length, + index, codePointOffset); } /** @@ -817,7 +772,7 @@ public final class String * This method doesn't perform any range checking. */ void getChars(char dst[], int dstBegin) { - System.arraycopy(value, offset, dst, dstBegin, count); + System.arraycopy(value, 0, dst, dstBegin, value.length); } /** @@ -854,14 +809,13 @@ public final class String if (srcBegin < 0) { throw new StringIndexOutOfBoundsException(srcBegin); } - if (srcEnd > count) { + if (srcEnd > value.length) { throw new StringIndexOutOfBoundsException(srcEnd); } if (srcBegin > srcEnd) { throw new StringIndexOutOfBoundsException(srcEnd - srcBegin); } - System.arraycopy(value, offset + srcBegin, dst, dstBegin, - srcEnd - srcBegin); + System.arraycopy(value, srcBegin, dst, dstBegin, srcEnd - srcBegin); } /** @@ -912,15 +866,15 @@ public final class String if (srcBegin < 0) { throw new StringIndexOutOfBoundsException(srcBegin); } - if (srcEnd > count) { + if (srcEnd > value.length) { throw new StringIndexOutOfBoundsException(srcEnd); } if (srcBegin > srcEnd) { throw new StringIndexOutOfBoundsException(srcEnd - srcBegin); } int j = dstBegin; - int n = offset + srcEnd; - int i = offset + srcBegin; + int n = srcEnd; + int i = srcBegin; char[] val = value; /* avoid getfield opcode */ while (i < n) { @@ -949,10 +903,9 @@ public final class String * @since JDK1.1 */ public byte[] getBytes(String charsetName) - throws UnsupportedEncodingException - { + throws UnsupportedEncodingException { if (charsetName == null) throw new NullPointerException(); - return StringCoding.encode(charsetName, value, offset, count); + return StringCoding.encode(charsetName, value, 0, value.length); } /** @@ -975,7 +928,7 @@ public final class String */ public byte[] getBytes(Charset charset) { if (charset == null) throw new NullPointerException(); - return StringCoding.encode(charset, value, offset, count); + return StringCoding.encode(charset, value, 0, value.length); } /** @@ -992,7 +945,7 @@ public final class String * @since JDK1.1 */ public byte[] getBytes() { - return StringCoding.encode(value, offset, count); + return StringCoding.encode(value, 0, value.length); } /** @@ -1015,16 +968,16 @@ public final class String return true; } if (anObject instanceof String) { - String anotherString = (String)anObject; - int n = count; - if (n == anotherString.count) { + String anotherString = (String) anObject; + int n = value.length; + if (n == anotherString.value.length) { char v1[] = value; char v2[] = anotherString.value; - int i = offset; - int j = anotherString.offset; + int i = 0; while (n-- != 0) { - if (v1[i++] != v2[j++]) - return false; + if (v1[i] != v2[i]) + return false; + i++; } return true; } @@ -1047,8 +1000,8 @@ public final class String * @since 1.4 */ public boolean contentEquals(StringBuffer sb) { - synchronized(sb) { - return contentEquals((CharSequence)sb); + synchronized (sb) { + return contentEquals((CharSequence) sb); } } @@ -1067,18 +1020,18 @@ public final class String * @since 1.5 */ public boolean contentEquals(CharSequence cs) { - if (count != cs.length()) + if (value.length != cs.length()) return false; // Argument is a StringBuffer, StringBuilder if (cs instanceof AbstractStringBuilder) { char v1[] = value; - char v2[] = ((AbstractStringBuilder)cs).getValue(); - int i = offset; - int j = 0; - int n = count; + char v2[] = ((AbstractStringBuilder) cs).getValue(); + int i = 0; + int n = value.length; while (n-- != 0) { - if (v1[i++] != v2[j++]) + if (v1[i] != v2[i]) return false; + i++; } return true; } @@ -1087,12 +1040,12 @@ public final class String return true; // Argument is a generic CharSequence char v1[] = value; - int i = offset; - int j = 0; - int n = count; + int i = 0; + int n = value.length; while (n-- != 0) { - if (v1[i++] != cs.charAt(j++)) + if (v1[i] != cs.charAt(i)) return false; + i++; } return true; } @@ -1126,9 +1079,10 @@ public final class String * @see #equals(Object) */ public boolean equalsIgnoreCase(String anotherString) { - return (this == anotherString) ? true : - (anotherString != null) && (anotherString.count == count) && - regionMatches(true, 0, anotherString, 0, count); + return (this == anotherString) ? true + : (anotherString != null) + && (anotherString.value.length == value.length) + && regionMatches(true, 0, anotherString, 0, value.length); } /** @@ -1173,33 +1127,20 @@ public final class String * lexicographically greater than the string argument. */ public int compareTo(String anotherString) { - int len1 = count; - int len2 = anotherString.count; - int n = Math.min(len1, len2); + int len1 = value.length; + int len2 = anotherString.value.length; + int lim = Math.min(len1, len2); char v1[] = value; char v2[] = anotherString.value; - int i = offset; - int j = anotherString.offset; - if (i == j) { - int k = i; - int lim = n + i; - while (k < lim) { - char c1 = v1[k]; - char c2 = v2[k]; - if (c1 != c2) { - return c1 - c2; - } - k++; - } - } else { - while (n-- != 0) { - char c1 = v1[i++]; - char c2 = v2[j++]; - if (c1 != c2) { - return c1 - c2; - } + int k = 0; + while (k < lim) { + char c1 = v1[k]; + char c2 = v2[k]; + if (c1 != c2) { + return c1 - c2; } + k++; } return len1 - len2; } @@ -1219,7 +1160,7 @@ public final class String public static final Comparator CASE_INSENSITIVE_ORDER = new CaseInsensitiveComparator(); private static class CaseInsensitiveComparator - implements Comparator, java.io.Serializable { + implements Comparator, java.io.Serializable { // use serialVersionUID from JDK 1.2.2 for interoperability private static final long serialVersionUID = 8575799808933029326L; @@ -1306,14 +1247,15 @@ public final class String * {@code false} otherwise. */ public boolean regionMatches(int toffset, String other, int ooffset, - int len) { + int len) { char ta[] = value; - int to = offset + toffset; + int to = toffset; char pa[] = other.value; - int po = other.offset + ooffset; + int po = ooffset; // Note: toffset, ooffset, or len might be near -1>>>1. - if ((ooffset < 0) || (toffset < 0) || (toffset > (long)count - len) - || (ooffset > (long)other.count - len)) { + if ((ooffset < 0) || (toffset < 0) + || (toffset > (long)value.length - len) + || (ooffset > (long)other.value.length - len)) { return false; } while (len-- > 0) { @@ -1351,7 +1293,7 @@ public final class String * integer k less than len such that: * 
      * Character.toLowerCase(this.charAt(toffset+k)) !=
-               Character.toLowerCase(other.charAt(ooffset+k))
+     Character.toLowerCase(other.charAt(ooffset+k))
      *
* and: * 
@@ -1375,14 +1317,15 @@ public final class String
      *          argument.
      */
     public boolean regionMatches(boolean ignoreCase, int toffset,
-                           String other, int ooffset, int len) {
+            String other, int ooffset, int len) {
         char ta[] = value;
-        int to = offset + toffset;
+        int to = toffset;
         char pa[] = other.value;
-        int po = other.offset + ooffset;
+        int po = ooffset;
         // Note: toffset, ooffset, or len might be near -1>>>1.
-        if ((ooffset < 0) || (toffset < 0) || (toffset > (long)count - len) ||
-                (ooffset > (long)other.count - len)) {
+        if ((ooffset < 0) || (toffset < 0)
+                || (toffset > (long)value.length - len)
+                || (ooffset > (long)other.value.length - len)) {
             return false;
         }
         while (len-- > 0) {
@@ -1433,12 +1376,12 @@ public final class String
      */
     public boolean startsWith(String prefix, int toffset) {
         char ta[] = value;
-        int to = offset + toffset;
+        int to = toffset;
         char pa[] = prefix.value;
-        int po = prefix.offset;
-        int pc = prefix.count;
+        int po = 0;
+        int pc = prefix.value.length;
         // Note: toffset might be near -1>>>1.
-        if ((toffset < 0) || (toffset > count - pc)) {
+        if ((toffset < 0) || (toffset > value.length - pc)) {
             return false;
         }
         while (--pc >= 0) {
@@ -1478,7 +1421,7 @@ public final class String
      *          as determined by the {@link #equals(Object)} method.
      */
     public boolean endsWith(String suffix) {
-        return startsWith(suffix, count - suffix.count);
+        return startsWith(suffix, value.length - suffix.value.length);
     }
 
     /**
@@ -1496,13 +1439,11 @@ public final class String
      */
     public int hashCode() {
         int h = hash;
-        if (h == 0 && count > 0) {
-            int off = offset;
+        if (h == 0 && value.length > 0) {
             char val[] = value;
-            int len = count;
 
-            for (int i = 0; i < len; i++) {
-                h = 31*h + val[off++];
+            for (int i = 0; i < value.length; i++) {
+                h = 31 * h + val[i];
             }
             hash = h;
         }
@@ -1577,9 +1518,10 @@ public final class String
      *          if the character does not occur.
      */
     public int indexOf(int ch, int fromIndex) {
+        final int max = value.length;
         if (fromIndex < 0) {
             fromIndex = 0;
-        } else if (fromIndex >= count) {
+        } else if (fromIndex >= max) {
             // Note: fromIndex might be near -1>>>1.
             return -1;
         }
@@ -1588,11 +1530,9 @@ public final class String
             // handle most cases here (ch is a BMP code point or a
             // negative value (invalid code point))
             final char[] value = this.value;
-            final int offset = this.offset;
-            final int max = offset + count;
-            for (int i = offset + fromIndex; i < max ; i++) {
+            for (int i = fromIndex; i < max; i++) {
                 if (value[i] == ch) {
-                    return i - offset;
+                    return i;
                 }
             }
             return -1;
@@ -1607,13 +1547,12 @@ public final class String
     private int indexOfSupplementary(int ch, int fromIndex) {
         if (Character.isValidCodePoint(ch)) {
             final char[] value = this.value;
-            final int offset = this.offset;
             final char hi = Character.highSurrogate(ch);
             final char lo = Character.lowSurrogate(ch);
-            final int max = offset + count - 1;
-            for (int i = offset + fromIndex; i < max; i++) {
-                if (value[i] == hi && value[i+1] == lo) {
-                    return i - offset;
+            final int max = value.length - 1;
+            for (int i = fromIndex; i < max; i++) {
+                if (value[i] == hi && value[i + 1] == lo) {
+                    return i;
                 }
             }
         }
@@ -1644,7 +1583,7 @@ public final class String
      *          {@code -1} if the character does not occur.
      */
     public int lastIndexOf(int ch) {
-        return lastIndexOf(ch, count - 1);
+        return lastIndexOf(ch, value.length - 1);
     }
 
     /**
@@ -1686,11 +1625,10 @@ public final class String
             // handle most cases here (ch is a BMP code point or a
             // negative value (invalid code point))
             final char[] value = this.value;
-            final int offset = this.offset;
-            int i = offset + Math.min(fromIndex, count - 1);
-            for (; i >= offset ; i--) {
+            int i = Math.min(fromIndex, value.length - 1);
+            for (; i >= 0; i--) {
                 if (value[i] == ch) {
-                    return i - offset;
+                    return i;
                 }
             }
             return -1;
@@ -1705,13 +1643,12 @@ public final class String
     private int lastIndexOfSupplementary(int ch, int fromIndex) {
         if (Character.isValidCodePoint(ch)) {
             final char[] value = this.value;
-            final int offset = this.offset;
             char hi = Character.highSurrogate(ch);
             char lo = Character.lowSurrogate(ch);
-            int i = offset + Math.min(fromIndex, count - 2);
-            for (; i >= offset; i--) {
-                if (value[i] == hi && value[i+1] == lo) {
-                    return i - offset;
+            int i = Math.min(fromIndex, value.length - 2);
+            for (; i >= 0; i--) {
+                if (value[i] == hi && value[i + 1] == lo) {
+                    return i;
                 }
             }
         }
@@ -1753,8 +1690,8 @@ public final class String
      *          or {@code -1} if there is no such occurrence.
      */
     public int indexOf(String str, int fromIndex) {
-        return indexOf(value, offset, count,
-                       str.value, str.offset, str.count, fromIndex);
+        return indexOf(value, 0, value.length,
+                str.value, 0, str.value.length, fromIndex);
     }
 
     /**
@@ -1771,8 +1708,8 @@ public final class String
      * @param   fromIndex    the index to begin searching from.
      */
     static int indexOf(char[] source, int sourceOffset, int sourceCount,
-                       char[] target, int targetOffset, int targetCount,
-                       int fromIndex) {
+            char[] target, int targetOffset, int targetCount,
+            int fromIndex) {
         if (fromIndex >= sourceCount) {
             return (targetCount == 0 ? sourceCount : -1);
         }
@@ -1783,7 +1720,7 @@ public final class String
             return fromIndex;
         }
 
-        char first  = target[targetOffset];
+        char first = target[targetOffset];
         int max = sourceOffset + (sourceCount - targetCount);
 
         for (int i = sourceOffset + fromIndex; i <= max; i++) {
@@ -1796,8 +1733,8 @@ public final class String
             if (i <= max) {
                 int j = i + 1;
                 int end = j + targetCount - 1;
-                for (int k = targetOffset + 1; j < end && source[j] ==
-                         target[k]; j++, k++);
+                for (int k = targetOffset + 1; j < end && source[j]
+                        == target[k]; j++, k++);
 
                 if (j == end) {
                     /* Found whole string. */
@@ -1824,7 +1761,7 @@ public final class String
      *          or {@code -1} if there is no such occurrence.
      */
     public int lastIndexOf(String str) {
-        return lastIndexOf(str, count);
+        return lastIndexOf(str, value.length);
     }
 
     /**
@@ -1844,8 +1781,8 @@ public final class String
      *          or {@code -1} if there is no such occurrence.
      */
     public int lastIndexOf(String str, int fromIndex) {
-        return lastIndexOf(value, offset, count,
-                           str.value, str.offset, str.count, fromIndex);
+        return lastIndexOf(value, 0, value.length,
+                str.value, 0, str.value.length, fromIndex);
     }
 
     /**
@@ -1862,8 +1799,8 @@ public final class String
      * @param   fromIndex    the index to begin searching from.
      */
     static int lastIndexOf(char[] source, int sourceOffset, int sourceCount,
-                           char[] target, int targetOffset, int targetCount,
-                           int fromIndex) {
+            char[] target, int targetOffset, int targetCount,
+            int fromIndex) {
         /*
          * Check arguments; return immediately where possible. For
          * consistency, don't check for null str.
@@ -1885,7 +1822,7 @@ public final class String
         int min = sourceOffset + targetCount - 1;
         int i = min + fromIndex;
 
-    startSearchForLastChar:
+        startSearchForLastChar:
         while (true) {
             while (i >= min && source[i] != strLastChar) {
                 i--;
@@ -1925,7 +1862,14 @@ public final class String
      *             length of this {@code String} object.
      */
     public String substring(int beginIndex) {
-        return substring(beginIndex, count);
+        if (beginIndex < 0) {
+            throw new StringIndexOutOfBoundsException(beginIndex);
+        }
+        int subLen = value.length - beginIndex;
+        if (subLen < 0) {
+            throw new StringIndexOutOfBoundsException(subLen);
+        }
+        return (beginIndex == 0) ? this : new String(value, beginIndex, subLen);
     }
 
     /**
@@ -1954,14 +1898,15 @@ public final class String
         if (beginIndex < 0) {
             throw new StringIndexOutOfBoundsException(beginIndex);
         }
-        if (endIndex > count) {
+        if (endIndex > value.length) {
             throw new StringIndexOutOfBoundsException(endIndex);
         }
-        if (beginIndex > endIndex) {
-            throw new StringIndexOutOfBoundsException(endIndex - beginIndex);
+        int subLen = endIndex - beginIndex;
+        if (subLen < 0) {
+            throw new StringIndexOutOfBoundsException(subLen);
         }
-        return ((beginIndex == 0) && (endIndex == count)) ? this :
-            new String(offset + beginIndex, endIndex - beginIndex, value);
+        return ((beginIndex == 0) && (endIndex == value.length)) ? this
+                : new String(value, beginIndex, subLen);
     }
 
     /**
@@ -2021,10 +1966,10 @@ public final class String
         if (otherLen == 0) {
             return this;
         }
-        char buf[] = new char[count + otherLen];
-        getChars(0, count, buf, 0);
-        str.getChars(0, otherLen, buf, count);
-        return new String(0, count + otherLen, buf);
+        int len = value.length;
+        char buf[] = Arrays.copyOf(value, len + otherLen);
+        str.getChars(buf, len);
+        return new String(buf, true);
     }
 
     /**
@@ -2058,27 +2003,26 @@ public final class String
      */
     public String replace(char oldChar, char newChar) {
         if (oldChar != newChar) {
-            int len = count;
+            int len = value.length;
             int i = -1;
             char[] val = value; /* avoid getfield opcode */
-            int off = offset;   /* avoid getfield opcode */
 
             while (++i < len) {
-                if (val[off + i] == oldChar) {
+                if (val[i] == oldChar) {
                     break;
                 }
             }
             if (i < len) {
                 char buf[] = new char[len];
-                for (int j = 0 ; j < i ; j++) {
-                    buf[j] = val[off+j];
+                for (int j = 0; j < i; j++) {
+                    buf[j] = val[j];
                 }
                 while (i < len) {
-                    char c = val[off + i];
+                    char c = val[i];
                     buf[i] = (c == oldChar) ? newChar : c;
                     i++;
                 }
-                return new String(0, len, buf);
+                return new String(buf, true);
             }
         }
         return this;
@@ -2229,7 +2173,7 @@ public final class String
      */
     public String replace(CharSequence target, CharSequence replacement) {
         return Pattern.compile(target.toString(), Pattern.LITERAL).matcher(
-            this).replaceAll(Matcher.quoteReplacement(replacement.toString()));
+                this).replaceAll(Matcher.quoteReplacement(replacement.toString()));
     }
 
     /**
@@ -2314,13 +2258,13 @@ public final class String
      */
     public String[] split(String regex, int limit) {
         /* fastpath if the regex is a
-           (1)one-char String and this character is not one of the
-              RegEx's meta characters ".$|()[{^?*+\\", or
-           (2)two-char String and the first char is the backslash and
-              the second is not the ascii digit or ascii letter.
-        */
+         (1)one-char String and this character is not one of the
+            RegEx's meta characters ".$|()[{^?*+\\", or
+         (2)two-char String and the first char is the backslash and
+            the second is not the ascii digit or ascii letter.
+         */
         char ch = 0;
-        if (((regex.count == 1 &&
+        if (((regex.value.length == 1 &&
              ".$|()[{^?*+\\".indexOf(ch = regex.charAt(0)) == -1) ||
              (regex.length() == 2 &&
               regex.charAt(0) == '\\' &&
@@ -2340,23 +2284,23 @@ public final class String
                     off = next + 1;
                 } else {    // last one
                     //assert (list.size() == limit - 1);
-                    list.add(substring(off, count));
-                    off = count;
+                    list.add(substring(off, value.length));
+                    off = value.length;
                     break;
                 }
             }
             // If no match was found, return this
             if (off == 0)
-                return new String[] { this };
+                return new String[]{this};
 
             // Add remaining segment
             if (!limited || list.size() < limit)
-                list.add(substring(off, count));
+                list.add(substring(off, value.length));
 
             // Construct result
             int resultSize = list.size();
             if (limit == 0)
-                while (resultSize > 0 && list.get(resultSize-1).length() == 0)
+                while (resultSize > 0 && list.get(resultSize - 1).length() == 0)
                     resultSize--;
             String[] result = new String[resultSize];
             return list.subList(0, resultSize).toArray(result);
@@ -2463,14 +2407,15 @@ public final class String
             throw new NullPointerException();
         }
 
-        int     firstUpper;
+        int firstUpper;
+        final int len = value.length;
 
         /* Now check if there are any characters that need to be changed. */
         scan: {
-            for (firstUpper = 0 ; firstUpper < count; ) {
-                char c = value[offset+firstUpper];
-                if ((c >= Character.MIN_HIGH_SURROGATE) &&
-                    (c <= Character.MAX_HIGH_SURROGATE)) {
+            for (firstUpper = 0 ; firstUpper < len; ) {
+                char c = value[firstUpper];
+                if ((c >= Character.MIN_HIGH_SURROGATE)
+                        && (c <= Character.MAX_HIGH_SURROGATE)) {
                     int supplChar = codePointAt(firstUpper);
                     if (supplChar != Character.toLowerCase(supplChar)) {
                         break scan;
@@ -2486,24 +2431,24 @@ public final class String
             return this;
         }
 
-        char[]  result = new char[count];
-        int     resultOffset = 0;  /* result may grow, so i+resultOffset
-                                    * is the write location in result */
+        char[] result = new char[len];
+        int resultOffset = 0;  /* result may grow, so i+resultOffset
+                                * is the write location in result */
 
         /* Just copy the first few lowerCase characters. */
-        System.arraycopy(value, offset, result, 0, firstUpper);
+        System.arraycopy(value, 0, result, 0, firstUpper);
 
         String lang = locale.getLanguage();
         boolean localeDependent =
-            (lang == "tr" || lang == "az" || lang == "lt");
+                (lang == "tr" || lang == "az" || lang == "lt");
         char[] lowerCharArray;
         int lowerChar;
         int srcChar;
         int srcCount;
-        for (int i = firstUpper; i < count; i += srcCount) {
-            srcChar = (int)value[offset+i];
-            if ((char)srcChar >= Character.MIN_HIGH_SURROGATE &&
-                (char)srcChar <= Character.MAX_HIGH_SURROGATE) {
+        for (int i = firstUpper; i < len; i += srcCount) {
+            srcChar = (int)value[i];
+            if ((char)srcChar >= Character.MIN_HIGH_SURROGATE
+                    && (char)srcChar <= Character.MAX_HIGH_SURROGATE) {
                 srcChar = codePointAt(i);
                 srcCount = Character.charCount(srcChar);
             } else {
@@ -2516,16 +2461,16 @@ public final class String
             } else {
                 lowerChar = Character.toLowerCase(srcChar);
             }
-            if ((lowerChar == Character.ERROR) ||
-                (lowerChar >= Character.MIN_SUPPLEMENTARY_CODE_POINT)) {
+            if ((lowerChar == Character.ERROR)
+                    || (lowerChar >= Character.MIN_SUPPLEMENTARY_CODE_POINT)) {
                 if (lowerChar == Character.ERROR) {
-                     if (!localeDependent && srcChar == '\u0130') {
-                         lowerCharArray =
-                             ConditionalSpecialCasing.toLowerCaseCharArray(this, i, Locale.ENGLISH);
-                     } else {
+                    if (!localeDependent && srcChar == '\u0130') {
                         lowerCharArray =
-                            ConditionalSpecialCasing.toLowerCaseCharArray(this, i, locale);
-                     }
+                                ConditionalSpecialCasing.toLowerCaseCharArray(this, i, Locale.ENGLISH);
+                    } else {
+                        lowerCharArray =
+                                ConditionalSpecialCasing.toLowerCaseCharArray(this, i, locale);
+                    }
                 } else if (srcCount == 2) {
                     resultOffset += Character.toChars(lowerChar, result, i + resultOffset) - srcCount;
                     continue;
@@ -2537,19 +2482,18 @@ public final class String
                 int mapLen = lowerCharArray.length;
                 if (mapLen > srcCount) {
                     char[] result2 = new char[result.length + mapLen - srcCount];
-                    System.arraycopy(result, 0, result2, 0,
-                        i + resultOffset);
+                    System.arraycopy(result, 0, result2, 0, i + resultOffset);
                     result = result2;
                 }
-                for (int x=0; x= Character.MIN_HIGH_SURROGATE) &&
-                    (c <= Character.MAX_HIGH_SURROGATE)) {
+                if ((c >= Character.MIN_HIGH_SURROGATE)
+                        && (c <= Character.MAX_HIGH_SURROGATE)) {
                     c = codePointAt(firstLower);
                     srcCount = Character.charCount(c);
                 } else {
                     srcCount = 1;
                 }
                 int upperCaseChar = Character.toUpperCaseEx(c);
-                if ((upperCaseChar == Character.ERROR) ||
-                    (c != upperCaseChar)) {
+                if ((upperCaseChar == Character.ERROR)
+                        || (c != upperCaseChar)) {
                     break scan;
                 }
                 firstLower += srcCount;
@@ -2652,22 +2597,22 @@ public final class String
             return this;
         }
 
-        char[]  result       = new char[count]; /* may grow */
-        int     resultOffset = 0;  /* result may grow, so i+resultOffset
-                                    * is the write location in result */
+        char[] result = new char[len]; /* may grow */
+        int resultOffset = 0;  /* result may grow, so i+resultOffset
+         * is the write location in result */
 
         /* Just copy the first few upperCase characters. */
-        System.arraycopy(value, offset, result, 0, firstLower);
+        System.arraycopy(value, 0, result, 0, firstLower);
 
         String lang = locale.getLanguage();
         boolean localeDependent =
-            (lang == "tr" || lang == "az" || lang == "lt");
+                (lang == "tr" || lang == "az" || lang == "lt");
         char[] upperCharArray;
         int upperChar;
         int srcChar;
         int srcCount;
-        for (int i = firstLower; i < count; i += srcCount) {
-            srcChar = (int)value[offset+i];
+        for (int i = firstLower; i < len; i += srcCount) {
+            srcChar = (int)value[i];
             if ((char)srcChar >= Character.MIN_HIGH_SURROGATE &&
                 (char)srcChar <= Character.MAX_HIGH_SURROGATE) {
                 srcChar = codePointAt(i);
@@ -2680,12 +2625,12 @@ public final class String
             } else {
                 upperChar = Character.toUpperCaseEx(srcChar);
             }
-            if ((upperChar == Character.ERROR) ||
-                (upperChar >= Character.MIN_SUPPLEMENTARY_CODE_POINT)) {
+            if ((upperChar == Character.ERROR)
+                    || (upperChar >= Character.MIN_SUPPLEMENTARY_CODE_POINT)) {
                 if (upperChar == Character.ERROR) {
                     if (localeDependent) {
                         upperCharArray =
-                            ConditionalSpecialCasing.toUpperCaseCharArray(this, i, locale);
+                                ConditionalSpecialCasing.toUpperCaseCharArray(this, i, locale);
                     } else {
                         upperCharArray = Character.toUpperCaseCharArray(srcChar);
                     }
@@ -2700,19 +2645,18 @@ public final class String
                 int mapLen = upperCharArray.length;
                 if (mapLen > srcCount) {
                     char[] result2 = new char[result.length + mapLen - srcCount];
-                    System.arraycopy(result, 0, result2, 0,
-                        i + resultOffset);
+                    System.arraycopy(result, 0, result2, 0, i + resultOffset);
                     result = result2;
                 }
-                for (int x=0; x 0) || (len < count)) ? substring(st, len) : this;
+        return ((st > 0) || (len < value.length)) ? substring(st, len) : this;
     }
 
     /**
@@ -2801,8 +2744,9 @@ public final class String
      *          the character sequence represented by this string.
      */
     public char[] toCharArray() {
-        char result[] = new char[count];
-        getChars(0, count, result, 0);
+        // Cannot use Arrays.copyOf because of class initialization order issues
+        char result[] = new char[value.length];
+        System.arraycopy(value, 0, result, 0, value.length);
         return result;
     }
 
@@ -2844,7 +2788,7 @@ public final class String
      * @see  java.util.Formatter
      * @since  1.5
      */
-    public static String format(String format, Object ... args) {
+    public static String format(String format, Object... args) {
         return new Formatter().format(format, args).toString();
     }
 
@@ -2888,7 +2832,7 @@ public final class String
      * @see  java.util.Formatter
      * @since  1.5
      */
-    public static String format(Locale l, String format, Object ... args) {
+    public static String format(Locale l, String format, Object... args) {
         return new Formatter(l).format(format, args).toString();
     }
 
@@ -2968,7 +2912,7 @@ public final class String
      *          character array.
      */
     public static String copyValueOf(char data[]) {
-        return copyValueOf(data, 0, data.length);
+        return new String(data);
     }
 
     /**
@@ -2993,7 +2937,7 @@ public final class String
      */
     public static String valueOf(char c) {
         char data[] = {c};
-        return new String(0, 1, data);
+        return new String(data, true);
     }
 
     /**
diff --git a/jdk/src/share/classes/java/lang/StringCoding.java b/jdk/src/share/classes/java/lang/StringCoding.java
index 95fb45ab659..2c08a0d0bb5 100644
--- a/jdk/src/share/classes/java/lang/StringCoding.java
+++ b/jdk/src/share/classes/java/lang/StringCoding.java
@@ -250,6 +250,7 @@ class StringCoding {
     static char[] decode(byte[] ba, int off, int len) {
         String csn = Charset.defaultCharset().name();
         try {
+            // use charset name decode() variant which provides caching.
             return decode(csn, ba, off, len);
         } catch (UnsupportedEncodingException x) {
             warnUnsupportedCharset(csn);
@@ -382,6 +383,7 @@ class StringCoding {
     static byte[] encode(char[] ca, int off, int len) {
         String csn = Charset.defaultCharset().name();
         try {
+            // use charset name encode() variant which provides caching.
             return encode(csn, ca, off, len);
         } catch (UnsupportedEncodingException x) {
             warnUnsupportedCharset(csn);