| // © 2017 and later: Unicode, Inc. and others. |
| // License & terms of use: http://www.unicode.org/copyright.html#License |
| package com.ibm.icu.impl; |
| |
| import java.text.Format.Field; |
| import java.util.Arrays; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| // NumberFormat is imported only for the toDebugString() implementation. |
| import com.ibm.icu.text.NumberFormat; |
| |
| /** |
| * A StringBuilder optimized for formatting. It implements the following key features beyond a |
| * normal JDK StringBuilder: |
| * |
| * <ol> |
| * <li>Efficient prepend as well as append. |
| * <li>Keeps tracks of Fields in an efficient manner. |
| * <li>String operations are fast-pathed to code point operations when possible. |
| * </ol> |
| * |
| * See also FormattedValueStringBuilderImpl. |
| * |
| * @author sffc (Shane Carr) |
| */ |
| public class FormattedStringBuilder implements CharSequence { |
| |
| /** A constant, empty FormattedStringBuilder. Do NOT call mutative operations on this. */ |
| public static final FormattedStringBuilder EMPTY = new FormattedStringBuilder(); |
| |
| char[] chars; |
| Field[] fields; |
| int zero; |
| int length; |
| |
| public FormattedStringBuilder() { |
| this(40); |
| } |
| |
| public FormattedStringBuilder(int capacity) { |
| chars = new char[capacity]; |
| fields = new Field[capacity]; |
| zero = capacity / 2; |
| length = 0; |
| } |
| |
| public FormattedStringBuilder(FormattedStringBuilder source) { |
| copyFrom(source); |
| } |
| |
| public void copyFrom(FormattedStringBuilder source) { |
| chars = Arrays.copyOf(source.chars, source.chars.length); |
| fields = Arrays.copyOf(source.fields, source.fields.length); |
| zero = source.zero; |
| length = source.length; |
| } |
| |
| @Override |
| public int length() { |
| return length; |
| } |
| |
| public int codePointCount() { |
| return Character.codePointCount(this, 0, length()); |
| } |
| |
| @Override |
| public char charAt(int index) { |
| assert index >= 0; |
| assert index < length; |
| return chars[zero + index]; |
| } |
| |
| public Field fieldAt(int index) { |
| assert index >= 0; |
| assert index < length; |
| return fields[zero + index]; |
| } |
| |
| public int getFirstCodePoint() { |
| if (length == 0) { |
| return -1; |
| } |
| return Character.codePointAt(chars, zero, zero + length); |
| } |
| |
| public int getLastCodePoint() { |
| if (length == 0) { |
| return -1; |
| } |
| return Character.codePointBefore(chars, zero + length, zero); |
| } |
| |
| public int codePointAt(int index) { |
| return Character.codePointAt(chars, zero + index, zero + length); |
| } |
| |
| public int codePointBefore(int index) { |
| return Character.codePointBefore(chars, zero + index, zero); |
| } |
| |
| public FormattedStringBuilder clear() { |
| zero = getCapacity() / 2; |
| length = 0; |
| return this; |
| } |
| |
| public int appendChar16(char codeUnit, Field field) { |
| return insertChar16(length, codeUnit, field); |
| } |
| |
| public int insertChar16(int index, char codeUnit, Field field) { |
| int count = 1; |
| int position = prepareForInsert(index, count); |
| chars[position] = codeUnit; |
| fields[position] = field; |
| return count; |
| } |
| |
| /** |
| * Appends the specified codePoint to the end of the string. |
| * |
| * @return The number of chars added: 1 if the code point is in the BMP, or 2 otherwise. |
| */ |
| public int appendCodePoint(int codePoint, Field field) { |
| return insertCodePoint(length, codePoint, field); |
| } |
| |
| /** |
| * Inserts the specified codePoint at the specified index in the string. |
| * |
| * @return The number of chars added: 1 if the code point is in the BMP, or 2 otherwise. |
| */ |
| public int insertCodePoint(int index, int codePoint, Field field) { |
| int count = Character.charCount(codePoint); |
| int position = prepareForInsert(index, count); |
| Character.toChars(codePoint, chars, position); |
| fields[position] = field; |
| if (count == 2) |
| fields[position + 1] = field; |
| return count; |
| } |
| |
| /** |
| * Appends the specified CharSequence to the end of the string. |
| * |
| * @return The number of chars added, which is the length of CharSequence. |
| */ |
| public int append(CharSequence sequence, Field field) { |
| return insert(length, sequence, field); |
| } |
| |
| /** |
| * Inserts the specified CharSequence at the specified index in the string. |
| * |
| * @return The number of chars added, which is the length of CharSequence. |
| */ |
| public int insert(int index, CharSequence sequence, Field field) { |
| if (sequence.length() == 0) { |
| // Nothing to insert. |
| return 0; |
| } else if (sequence.length() == 1) { |
| // Fast path: on a single-char string, using insertCodePoint below is 70% faster than the |
| // CharSequence method: 12.2 ns versus 41.9 ns for five operations on my Linux x86-64. |
| return insertCodePoint(index, sequence.charAt(0), field); |
| } else { |
| return insert(index, sequence, 0, sequence.length(), field); |
| } |
| } |
| |
| /** |
| * Inserts the specified CharSequence at the specified index in the string, reading from the |
| * CharSequence from start (inclusive) to end (exclusive). |
| * |
| * @return The number of chars added, which is the length of CharSequence. |
| */ |
| public int insert(int index, CharSequence sequence, int start, int end, Field field) { |
| int count = end - start; |
| int position = prepareForInsert(index, count); |
| for (int i = 0; i < count; i++) { |
| chars[position + i] = sequence.charAt(start + i); |
| fields[position + i] = field; |
| } |
| return count; |
| } |
| |
| /** |
| * Replaces the chars between startThis and endThis with the chars between startOther and endOther of |
| * the given CharSequence. Calling this method with startThis == endThis is equivalent to calling |
| * insert. |
| * |
| * @return The number of chars added, which may be negative if the removed segment is longer than the |
| * length of the CharSequence segment that was inserted. |
| */ |
| public int splice( |
| int startThis, |
| int endThis, |
| CharSequence sequence, |
| int startOther, |
| int endOther, |
| Field field) { |
| int thisLength = endThis - startThis; |
| int otherLength = endOther - startOther; |
| int count = otherLength - thisLength; |
| int position; |
| if (count > 0) { |
| // Overall, chars need to be added. |
| position = prepareForInsert(startThis, count); |
| } else { |
| // Overall, chars need to be removed or kept the same. |
| position = remove(startThis, -count); |
| } |
| for (int i = 0; i < otherLength; i++) { |
| chars[position + i] = sequence.charAt(startOther + i); |
| fields[position + i] = field; |
| } |
| return count; |
| } |
| |
| /** |
| * Appends the chars in the specified char array to the end of the string, and associates them with |
| * the fields in the specified field array, which must have the same length as chars. |
| * |
| * @return The number of chars added, which is the length of the char array. |
| */ |
| public int append(char[] chars, Field[] fields) { |
| return insert(length, chars, fields); |
| } |
| |
| /** |
| * Inserts the chars in the specified char array at the specified index in the string, and associates |
| * them with the fields in the specified field array, which must have the same length as chars. |
| * |
| * @return The number of chars added, which is the length of the char array. |
| */ |
| public int insert(int index, char[] chars, Field[] fields) { |
| assert fields == null || chars.length == fields.length; |
| int count = chars.length; |
| if (count == 0) |
| return 0; // nothing to insert |
| int position = prepareForInsert(index, count); |
| for (int i = 0; i < count; i++) { |
| this.chars[position + i] = chars[i]; |
| this.fields[position + i] = fields == null ? null : fields[i]; |
| } |
| return count; |
| } |
| |
| /** |
| * Appends the contents of another {@link FormattedStringBuilder} to the end of this instance. |
| * |
| * @return The number of chars added, which is the length of the other {@link FormattedStringBuilder}. |
| */ |
| public int append(FormattedStringBuilder other) { |
| return insert(length, other); |
| } |
| |
| /** |
| * Inserts the contents of another {@link FormattedStringBuilder} into this instance at the given index. |
| * |
| * @return The number of chars added, which is the length of the other {@link FormattedStringBuilder}. |
| */ |
| public int insert(int index, FormattedStringBuilder other) { |
| if (this == other) { |
| throw new IllegalArgumentException("Cannot call insert/append on myself"); |
| } |
| int count = other.length; |
| if (count == 0) { |
| // Nothing to insert. |
| return 0; |
| } |
| int position = prepareForInsert(index, count); |
| for (int i = 0; i < count; i++) { |
| this.chars[position + i] = other.charAt(i); |
| this.fields[position + i] = other.fieldAt(i); |
| } |
| return count; |
| } |
| |
| /** |
| * Shifts around existing data if necessary to make room for new characters. |
| * |
| * @param index |
| * The location in the string where the operation is to take place. |
| * @param count |
| * The number of chars (UTF-16 code units) to be inserted at that location. |
| * @return The position in the char array to insert the chars. |
| */ |
| private int prepareForInsert(int index, int count) { |
| if (index == 0 && zero - count >= 0) { |
| // Append to start |
| zero -= count; |
| length += count; |
| return zero; |
| } else if (index == length && zero + length + count < getCapacity()) { |
| // Append to end |
| length += count; |
| return zero + length - count; |
| } else { |
| // Move chars around and/or allocate more space |
| return prepareForInsertHelper(index, count); |
| } |
| } |
| |
| private int prepareForInsertHelper(int index, int count) { |
| // Java note: Keeping this code out of prepareForInsert() increases the speed of append |
| // operations. |
| int oldCapacity = getCapacity(); |
| int oldZero = zero; |
| char[] oldChars = chars; |
| Field[] oldFields = fields; |
| if (length + count > oldCapacity) { |
| int newCapacity = (length + count) * 2; |
| int newZero = newCapacity / 2 - (length + count) / 2; |
| |
| char[] newChars = new char[newCapacity]; |
| Field[] newFields = new Field[newCapacity]; |
| |
| // First copy the prefix and then the suffix, leaving room for the new chars that the |
| // caller wants to insert. |
| System.arraycopy(oldChars, oldZero, newChars, newZero, index); |
| System.arraycopy(oldChars, |
| oldZero + index, |
| newChars, |
| newZero + index + count, |
| length - index); |
| System.arraycopy(oldFields, oldZero, newFields, newZero, index); |
| System.arraycopy(oldFields, |
| oldZero + index, |
| newFields, |
| newZero + index + count, |
| length - index); |
| |
| chars = newChars; |
| fields = newFields; |
| zero = newZero; |
| length += count; |
| } else { |
| int newZero = oldCapacity / 2 - (length + count) / 2; |
| |
| // First copy the entire string to the location of the prefix, and then move the suffix |
| // to make room for the new chars that the caller wants to insert. |
| System.arraycopy(oldChars, oldZero, oldChars, newZero, length); |
| System.arraycopy(oldChars, |
| newZero + index, |
| oldChars, |
| newZero + index + count, |
| length - index); |
| System.arraycopy(oldFields, oldZero, oldFields, newZero, length); |
| System.arraycopy(oldFields, |
| newZero + index, |
| oldFields, |
| newZero + index + count, |
| length - index); |
| |
| zero = newZero; |
| length += count; |
| } |
| return zero + index; |
| } |
| |
| /** |
| * Removes the "count" chars starting at "index". Returns the position at which the chars were |
| * removed. |
| */ |
| private int remove(int index, int count) { |
| int position = index + zero; |
| System.arraycopy(chars, position + count, chars, position, length - index - count); |
| System.arraycopy(fields, position + count, fields, position, length - index - count); |
| length -= count; |
| return position; |
| } |
| |
| private int getCapacity() { |
| return chars.length; |
| } |
| |
| /** Note: this returns a FormattedStringBuilder. Do not return publicly. */ |
| @Override |
| @Deprecated |
| public CharSequence subSequence(int start, int end) { |
| assert start >= 0; |
| assert end <= length; |
| assert end >= start; |
| FormattedStringBuilder other = new FormattedStringBuilder(this); |
| other.zero = zero + start; |
| other.length = end - start; |
| return other; |
| } |
| |
| /** Use this instead of subSequence if returning publicly. */ |
| public String subString(int start, int end) { |
| if (start < 0 || end > length || end < start) { |
| throw new IndexOutOfBoundsException(); |
| } |
| return new String(chars, start + zero, end - start); |
| } |
| |
| /** |
| * Returns the string represented by the characters in this string builder. |
| * |
| * <p> |
| * For a string intended be used for debugging, use {@link #toDebugString}. |
| */ |
| @Override |
| public String toString() { |
| return new String(chars, zero, length); |
| } |
| |
| private static final Map<Field, Character> fieldToDebugChar = new HashMap<>(); |
| |
| static { |
| fieldToDebugChar.put(NumberFormat.Field.SIGN, '-'); |
| fieldToDebugChar.put(NumberFormat.Field.INTEGER, 'i'); |
| fieldToDebugChar.put(NumberFormat.Field.FRACTION, 'f'); |
| fieldToDebugChar.put(NumberFormat.Field.EXPONENT, 'e'); |
| fieldToDebugChar.put(NumberFormat.Field.EXPONENT_SIGN, '+'); |
| fieldToDebugChar.put(NumberFormat.Field.EXPONENT_SYMBOL, 'E'); |
| fieldToDebugChar.put(NumberFormat.Field.DECIMAL_SEPARATOR, '.'); |
| fieldToDebugChar.put(NumberFormat.Field.GROUPING_SEPARATOR, ','); |
| fieldToDebugChar.put(NumberFormat.Field.PERCENT, '%'); |
| fieldToDebugChar.put(NumberFormat.Field.PERMILLE, '‰'); |
| fieldToDebugChar.put(NumberFormat.Field.CURRENCY, '$'); |
| fieldToDebugChar.put(NumberFormat.Field.MEASURE_UNIT, 'u'); |
| fieldToDebugChar.put(NumberFormat.Field.COMPACT, 'C'); |
| } |
| |
| /** |
| * Returns a string that includes field information, for debugging purposes. |
| * |
| * <p> |
| * For example, if the string is "-12.345", the debug string will be something like |
| * "<FormattedStringBuilder [-123.45] [-iii.ff]>" |
| * |
| * @return A string for debugging purposes. |
| */ |
| public String toDebugString() { |
| StringBuilder sb = new StringBuilder(); |
| sb.append("<FormattedStringBuilder ["); |
| sb.append(this.toString()); |
| sb.append("] ["); |
| for (int i = zero; i < zero + length; i++) { |
| if (fields[i] == null) { |
| sb.append('n'); |
| } else if (fieldToDebugChar.containsKey(fields[i])) { |
| sb.append(fieldToDebugChar.get(fields[i])); |
| } else { |
| sb.append('?'); |
| } |
| } |
| sb.append("]>"); |
| return sb.toString(); |
| } |
| |
| /** @return A new array containing the contents of this string builder. */ |
| public char[] toCharArray() { |
| return Arrays.copyOfRange(chars, zero, zero + length); |
| } |
| |
| /** @return A new array containing the field values of this string builder. */ |
| public Field[] toFieldArray() { |
| return Arrays.copyOfRange(fields, zero, zero + length); |
| } |
| |
| /** |
| * @return Whether the contents and field values of this string builder are equal to the given chars |
| * and fields. |
| * @see #toCharArray |
| * @see #toFieldArray |
| */ |
| public boolean contentEquals(char[] chars, Field[] fields) { |
| if (chars.length != length) |
| return false; |
| if (fields.length != length) |
| return false; |
| for (int i = 0; i < length; i++) { |
| if (this.chars[zero + i] != chars[i]) |
| return false; |
| if (this.fields[zero + i] != fields[i]) |
| return false; |
| } |
| return true; |
| } |
| |
| /** |
| * @param other |
| * The instance to compare. |
| * @return Whether the contents of this instance is currently equal to the given instance. |
| */ |
| public boolean contentEquals(FormattedStringBuilder other) { |
| if (length != other.length) |
| return false; |
| for (int i = 0; i < length; i++) { |
| if (charAt(i) != other.charAt(i) || fieldAt(i) != other.fieldAt(i)) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| @Override |
| public int hashCode() { |
| throw new UnsupportedOperationException("Don't call #hashCode() or #equals() on a mutable."); |
| } |
| |
| @Override |
| public boolean equals(Object other) { |
| throw new UnsupportedOperationException("Don't call #hashCode() or #equals() on a mutable."); |
| } |
| } |