This is an automated email from the ASF dual-hosted git repository. benweidig pushed a commit to branch TAP5-2837 in repository https://gitbox.apache.org/repos/asf/tapestry-5.git
commit b9a233cc52626b4855c923ca0061835130f25c13 Author: Ben Weidig <[email protected]> AuthorDate: Sun Jul 26 14:50:08 2026 +0200 TAP5-2837: Improve JSON serialization performance --- .../org/apache/tapestry5/json/CompactSession.java | 23 ++- .../org/apache/tapestry5/json/JSONCollection.java | 36 ++-- .../java/org/apache/tapestry5/json/JSONObject.java | 200 ++++++++++++++++++--- .../org/apache/tapestry5/json/JSONPrintSink.java | 92 ++++++++++ .../org/apache/tapestry5/json/JSONStringer.java | 3 + .../org/apache/tapestry5/json/JSONTokener.java | 4 +- .../apache/tapestry5/json/PrettyPrintSession.java | 41 +++-- .../org/apache/tapestry5/json/package-info.java | 4 +- .../org/apache/tapestry5/json/JSONObjectTest.java | 15 +- 9 files changed, 355 insertions(+), 63 deletions(-) diff --git a/tapestry-json/src/main/java/org/apache/tapestry5/json/CompactSession.java b/tapestry-json/src/main/java/org/apache/tapestry5/json/CompactSession.java index 8eced6925..55127a23a 100644 --- a/tapestry-json/src/main/java/org/apache/tapestry5/json/CompactSession.java +++ b/tapestry-json/src/main/java/org/apache/tapestry5/json/CompactSession.java @@ -1,4 +1,4 @@ -// Copyright 2010 The Apache Software Foundation +// Copyright 2010, 2026 The Apache Software Foundation // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. @@ -18,16 +18,21 @@ import java.io.PrintWriter; /** * Prints the JSON content compactly, with no indentation or extra whitespace. - * + * * @since 5.2.0 */ class CompactSession implements JSONPrintSession { - private final PrintWriter writer; + private final JSONPrintSink out; + + CompactSession(StringBuilder out) + { + this.out = new StringBuilderPrintSink(out); + } public CompactSession(PrintWriter writer) { - this.writer = writer; + this.out = new WriterPrintSink(writer); } @Override @@ -51,7 +56,7 @@ class CompactSession implements JSONPrintSession @Override public JSONPrintSession print(String value) { - writer.print(value); + out.append(value); return this; } @@ -59,13 +64,17 @@ class CompactSession implements JSONPrintSession @Override public JSONPrintSession printQuoted(String value) { - return print(JSONObject.quote(value)); + out.append('"'); + JSONObject.escapeInto(out, value); + out.append('"'); + + return this; } @Override public JSONPrintSession printSymbol(char symbol) { - writer.print(symbol); + out.append(symbol); return this; } diff --git a/tapestry-json/src/main/java/org/apache/tapestry5/json/JSONCollection.java b/tapestry-json/src/main/java/org/apache/tapestry5/json/JSONCollection.java index c5ee1082c..0615bc47a 100644 --- a/tapestry-json/src/main/java/org/apache/tapestry5/json/JSONCollection.java +++ b/tapestry-json/src/main/java/org/apache/tapestry5/json/JSONCollection.java @@ -12,7 +12,6 @@ package org.apache.tapestry5.json; -import java.io.CharArrayWriter; import java.io.PrintWriter; import java.io.Serializable; @@ -38,16 +37,13 @@ public abstract class JSONCollection implements Serializable @Override public String toString() { - CharArrayWriter caw = new CharArrayWriter(); - PrintWriter pw = new PrintWriter(caw); + StringBuilder out = new StringBuilder(estimateCapacity()); - JSONPrintSession session = new PrettyPrintSession(pw); + JSONPrintSession session = new PrettyPrintSession(out); print(session); - pw.close(); - - return caw.toString(); + return out.toString(); } /** @@ -68,16 +64,32 @@ public abstract class JSONCollection implements Serializable */ public String toCompactString() { - CharArrayWriter caw = new CharArrayWriter(); - PrintWriter pw = new PrintWriter(caw); + StringBuilder out = new StringBuilder(estimateCapacity()); - print(pw); + JSONPrintSession session = new CompactSession(out); - pw.close(); + print(session); - return caw.toString(); + return out.toString(); + } + + /** + * A cheap starting capacity for the {@link StringBuilder} backing {@link #toString()} / + * {@link #toCompactString()}, to avoid repeated grow-and-copy cycles for non-trivial trees. + * Scales with the top-level collection's element count only; recursing into nested + * collections isn't worth the extra bookkeeping for a rough estimate. + */ + private int estimateCapacity() + { + return Math.max(256, size() * 32); } + /** + * The number of top-level entries (name/value pairs for {@link JSONObject}, elements for + * {@link JSONArray}), used only to estimate a starting buffer capacity. + */ + abstract int size(); + /** * Prints the JSONObject to the write (compactly or not). * diff --git a/tapestry-json/src/main/java/org/apache/tapestry5/json/JSONObject.java b/tapestry-json/src/main/java/org/apache/tapestry5/json/JSONObject.java index 321085ed5..b7f034549 100644 --- a/tapestry-json/src/main/java/org/apache/tapestry5/json/JSONObject.java +++ b/tapestry-json/src/main/java/org/apache/tapestry5/json/JSONObject.java @@ -775,14 +775,154 @@ public final class JSONObject extends JSONCollection implements Map<String, Obje if (data == null) { return "\"\""; } - try { - JSONStringer stringer = new JSONStringer(); - stringer.open(JSONStringer.Scope.NULL, ""); - stringer.string(data); - stringer.close(JSONStringer.Scope.NULL, JSONStringer.Scope.NULL, ""); - return stringer.toString(); - } catch (RuntimeException e) { - throw new AssertionError(); + + StringBuilder out = new StringBuilder(data.length() + 8); + out.append('"'); + escapeInto(out, data); + out.append('"'); + return out.toString(); + } + + private static final char[] HEX_DIGITS = "0123456789abcdef".toCharArray(); + + /** + * Appends the escaped (but not quoted) form of {@code value} to {@code out}: the same + * character escaping rules as {@link #quote(String)}, without allocating an intermediate + * String or wrapping quotes. + * + * <p>This is the direct-to-{@link StringBuilder} fast path used by {@code quote()} itself, + * which always targets a StringBuilder and is called often enough (once per printed string/key) + * that the {@link JSONPrintSink} indirection used by {@link #escapeInto(JSONPrintSink, String)} + * measurably costs more than it's worth here. See {@link #escapeInto(JSONPrintSink, String)} + * for the print-session variant. + */ + static void escapeInto(StringBuilder out, String value) { + char currentChar = 0; + + for (int i = 0, length = value.length(); i < length; i++) { + char previousChar = currentChar; + currentChar = value.charAt(i); + + /* + * From RFC 4627, "All Unicode characters may be placed within the + * quotation marks except for the characters that must be escaped: + * quotation mark, reverse solidus, and the control characters + * (U+0000 through U+001F)." + */ + switch (currentChar) { + case '"': + case '\\': + out.append('\\').append(currentChar); + break; + + case '/': + // it makes life easier for HTML embedding of javascript if we escape </ sequences + if (previousChar == '<') { + out.append('\\'); + } + out.append(currentChar); + break; + + case '\t': + out.append("\\t"); + break; + + case '\b': + out.append("\\b"); + break; + + case '\n': + out.append("\\n"); + break; + + case '\r': + out.append("\\r"); + break; + + case '\f': + out.append("\\f"); + break; + + default: + if (currentChar <= 0x1F || (currentChar >= 0x0080 && currentChar < 0x00a0) || (currentChar >= 0x2000 && currentChar < 0x2100)) { + out.append('\\').append('u') + .append(HEX_DIGITS[(currentChar >> 12) & 0xF]) + .append(HEX_DIGITS[(currentChar >> 8) & 0xF]) + .append(HEX_DIGITS[(currentChar >> 4) & 0xF]) + .append(HEX_DIGITS[currentChar & 0xF]); + } else { + out.append(currentChar); + } + break; + } + } + } + + /** + * Same escaping rules as {@link #escapeInto(StringBuilder, String)}, targeting a + * {@link JSONPrintSink} instead. + * + * <p>Used by the print sessions, whose destination varies between an in-memory + * {@link StringBuilder} ({@code toString()}/{@code toCompactString()}) and a + * caller-supplied {@link java.io.PrintWriter} ({@code print(PrintWriter, boolean)}), + * so they can escape directly into whichever one they were constructed with. + * + * <p>Note: Having dedicated methods for the types instead of a classifying mechanism + * keeps the call site monomorphic for the JVM, allowing for greater optimization + * potential. + */ + static void escapeInto(JSONPrintSink out, String value) { + char currentChar = 0; + + for (int i = 0, length = value.length(); i < length; i++) { + char previousChar = currentChar; + currentChar = value.charAt(i); + + switch (currentChar) { + case '"': + case '\\': + out.append('\\').append(currentChar); + break; + + case '/': + if (previousChar == '<') { + out.append('\\'); + } + out.append(currentChar); + break; + + case '\t': + out.append("\\t"); + break; + + case '\b': + out.append("\\b"); + break; + + case '\n': + out.append("\\n"); + break; + + case '\r': + out.append("\\r"); + break; + + case '\f': + out.append("\\f"); + break; + + default: + if (currentChar <= 0x1F || (currentChar >= 0x0080 && currentChar < 0x00a0) || (currentChar >= 0x2000 && currentChar < 0x2100)) { + out.append('\\').append('u') + .append(HEX_DIGITS[(currentChar >> 12) & 0xF]) + .append(HEX_DIGITS[(currentChar >> 8) & 0xF]) + .append(HEX_DIGITS[(currentChar >> 4) & 0xF]) + .append(HEX_DIGITS[currentChar & 0xF]); + } else { + out.append(currentChar); + } + break; + } } } @@ -826,7 +966,6 @@ public final class JSONObject extends JSONCollection implements Map<String, Obje session.printSymbol('}'); } - /** * Prints a value (a JSONArray or JSONObject, or a value stored in an array or object) using * the session. @@ -835,48 +974,61 @@ public final class JSONObject extends JSONCollection implements Map<String, Obje */ static void printValue(JSONPrintSession session, Object value) { + // Orderd by (assumed) most common frequency in JSON + // Null Check: Must be first. if (value == null || value == NULL) { session.print("null"); return; } - if (value instanceof JSONObject) - { - ((JSONObject) value).print(session); - return; - } - if (value instanceof JSONArray) + // String: Explicitly checking here prevents the most common + // JSON type from falling through all other checks. + if (value instanceof String) { - ((JSONArray) value).print(session); + session.printQuoted((String) value); return; } - if (value instanceof JSONString) + // Number: Highly common in JSON payloads. + if (value instanceof Number) { - String printValue = ((JSONString) value).toJSONString(); - + String printValue = numberToString((Number) value); session.print(printValue); - return; } - if (value instanceof Number) + // JSONObject: The primary structural container. + if (value instanceof JSONObject) { - String printValue = numberToString((Number) value); - session.print(printValue); + ((JSONObject) value).print(session); return; } + // Boolean: Common, but usually fewer instances per payload than numbers. if (value instanceof Boolean) { session.print(value.toString()); + return; + } + // JSONArray: Generally fewer arrays than objects in nested structures. + if (value instanceof JSONArray) + { + ((JSONArray) value).print(session); + return; + } + + // JSONString: Kept near the bottom assuming it is a custom wrapper. + if (value instanceof JSONString) + { + String printValue = ((JSONString) value).toJSONString(); + session.print(printValue); return; } - // Otherwise it really should just be a string. Nothing else can go in. + // Fallback for any other unexpected objects session.printQuoted(value.toString()); } diff --git a/tapestry-json/src/main/java/org/apache/tapestry5/json/JSONPrintSink.java b/tapestry-json/src/main/java/org/apache/tapestry5/json/JSONPrintSink.java new file mode 100644 index 000000000..ccd843af9 --- /dev/null +++ b/tapestry-json/src/main/java/org/apache/tapestry5/json/JSONPrintSink.java @@ -0,0 +1,92 @@ +// Copyright 2026 The Apache Software Foundation +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package org.apache.tapestry5.json; + +import java.io.PrintWriter; + +/** + * The destination a {@link JSONPrintSession} (and {@link JSONObject#escapeInto}) writes + * characters to: either an in-memory buffer (for {@code toString()}/{@code toCompactString()}) + * or a caller-supplied {@link PrintWriter} (for {@code print(PrintWriter, boolean)}). + * + * <p>Deliberately narrower than {@link Appendable}: neither implementation below can actually throw + * {@link java.io.IOException}, so this avoids forcing checked-exception handling onto every + * append call in the hot print path. + */ +interface JSONPrintSink +{ + JSONPrintSink append(String value); + + JSONPrintSink append(char value); +} + +/** + * Sink backed by an in-memory {@link StringBuilder}, used to build a {@code String} directly + * without an intermediate {@code CharArrayWriter}/{@code PrintWriter} pair. + */ +class StringBuilderPrintSink implements JSONPrintSink +{ + private final StringBuilder out; + + StringBuilderPrintSink(StringBuilder out) + { + this.out = out; + } + + @Override + public JSONPrintSink append(String value) + { + out.append(value); + + return this; + } + + @Override + public JSONPrintSink append(char value) + { + out.append(value); + + return this; + } +} + +/** + * Sink backed by a caller-supplied {@link PrintWriter}, used by {@code print(PrintWriter, boolean)}. + */ +class WriterPrintSink implements JSONPrintSink +{ + private final PrintWriter writer; + + WriterPrintSink(PrintWriter writer) + { + this.writer = writer; + } + + @Override + public JSONPrintSink append(String value) + { + writer.print(value); + + return this; + } + + @Override + public JSONPrintSink append(char value) + { + writer.write(value); + + return this; + } +} diff --git a/tapestry-json/src/main/java/org/apache/tapestry5/json/JSONStringer.java b/tapestry-json/src/main/java/org/apache/tapestry5/json/JSONStringer.java index 861263574..d49b6c3a1 100644 --- a/tapestry-json/src/main/java/org/apache/tapestry5/json/JSONStringer.java +++ b/tapestry-json/src/main/java/org/apache/tapestry5/json/JSONStringer.java @@ -57,7 +57,10 @@ import java.util.List; * self-use by overrideable methods is not specified. See <i>Effective Java</i> * Item 17, "Design and Document or inheritance or else prohibit it" for further * information. + * + * @deprecated in 5.10.0 without a replacement. */ +@Deprecated class JSONStringer { /** diff --git a/tapestry-json/src/main/java/org/apache/tapestry5/json/JSONTokener.java b/tapestry-json/src/main/java/org/apache/tapestry5/json/JSONTokener.java index e0c4dac3c..225c8c26c 100644 --- a/tapestry-json/src/main/java/org/apache/tapestry5/json/JSONTokener.java +++ b/tapestry-json/src/main/java/org/apache/tapestry5/json/JSONTokener.java @@ -476,14 +476,14 @@ class JSONTokener { case ',': case ';': /* A separator without a value first means "null". */ - result.put(JSONObject.NULL); + result.add(JSONObject.NULL); hasTrailingSeparator = true; continue; default: pos--; } - result.put(nextValue(null)); + result.add(nextValue(null)); switch (nextCleanInternal()) { case ']': diff --git a/tapestry-json/src/main/java/org/apache/tapestry5/json/PrettyPrintSession.java b/tapestry-json/src/main/java/org/apache/tapestry5/json/PrettyPrintSession.java index 8f0c5f31b..729f0c39b 100644 --- a/tapestry-json/src/main/java/org/apache/tapestry5/json/PrettyPrintSession.java +++ b/tapestry-json/src/main/java/org/apache/tapestry5/json/PrettyPrintSession.java @@ -1,4 +1,4 @@ -// Copyright 2010 The Apache Software Foundation +// Copyright 2010, 2026 The Apache Software Foundation // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. @@ -18,12 +18,12 @@ import java.io.PrintWriter; /** * Used to pretty-print JSON content, with a customizable indentation. - * + * * @since 5.2.0 */ class PrettyPrintSession implements JSONPrintSession { - private final PrintWriter writer; + private final JSONPrintSink out; private final String indentString; @@ -36,10 +36,16 @@ class PrettyPrintSession implements JSONPrintSession private Position position = Position.MARGIN; + /** Defaults the indentation to be two spaces per indentation level. */ + PrettyPrintSession(StringBuilder out) + { + this(new StringBuilderPrintSink(out), " "); + } + /** Defaults the indentation to be two spaces per indentation level. */ public PrettyPrintSession(PrintWriter writer) { - this(writer, " "); + this(new WriterPrintSink(writer), " "); } /** @@ -50,7 +56,12 @@ class PrettyPrintSession implements JSONPrintSession */ public PrettyPrintSession(PrintWriter writer, String indentString) { - this.writer = writer; + this(new WriterPrintSink(writer), indentString); + } + + private PrettyPrintSession(JSONPrintSink out, String indentString) + { + this.out = out; this.indentString = indentString; } @@ -67,7 +78,7 @@ class PrettyPrintSession implements JSONPrintSession { if (position != Position.MARGIN) { - writer.write('\n'); + out.append('\n'); position = Position.MARGIN; } @@ -87,7 +98,7 @@ class PrettyPrintSession implements JSONPrintSession if (position == Position.MARGIN) { for (int i = 0; i < indentLevel; i++) - writer.print(indentString); + out.append(indentString); position = Position.INDENTED; } @@ -97,7 +108,7 @@ class PrettyPrintSession implements JSONPrintSession { if (position == Position.CONTENT) { - writer.print(' '); + out.append(' '); } } @@ -113,7 +124,7 @@ class PrettyPrintSession implements JSONPrintSession { prepareToPrint(); - writer.print(value); + out.append(value); position = Position.CONTENT; @@ -123,7 +134,15 @@ class PrettyPrintSession implements JSONPrintSession @Override public JSONPrintSession printQuoted(String value) { - return print(JSONObject.quote(value)); + prepareToPrint(); + + out.append('"'); + JSONObject.escapeInto(out, value); + out.append('"'); + + position = Position.CONTENT; + + return this; } @Override @@ -134,7 +153,7 @@ class PrettyPrintSession implements JSONPrintSession if (symbol != ',') addSep(); - writer.print(symbol); + out.append(symbol); return this; } diff --git a/tapestry-json/src/main/java/org/apache/tapestry5/json/package-info.java b/tapestry-json/src/main/java/org/apache/tapestry5/json/package-info.java index 464082c05..2d5a6715a 100644 --- a/tapestry-json/src/main/java/org/apache/tapestry5/json/package-info.java +++ b/tapestry-json/src/main/java/org/apache/tapestry5/json/package-info.java @@ -13,7 +13,7 @@ /** * Repackaged, improved (and tested) version of code originally https://github.com/tdunning/open-json * - * Starting in release 5.4, {@link org.apache.tapestry5.json.JSONObject} and {@link org.apache.tapestry5.json.JSONArray} + * Starting in release 5.4, {@link org.apache.tapestry5.json.improved.JSONObject} and {@link org.apache.tapestry5.json.improved.JSONArray} * are serializable. */ -package org.apache.tapestry5.json; +package org.apache.tapestry5.json.improved; diff --git a/tapestry-json/src/test/java/org/apache/tapestry5/json/JSONObjectTest.java b/tapestry-json/src/test/java/org/apache/tapestry5/json/JSONObjectTest.java index 0b4167a80..64689de9d 100644 --- a/tapestry-json/src/test/java/org/apache/tapestry5/json/JSONObjectTest.java +++ b/tapestry-json/src/test/java/org/apache/tapestry5/json/JSONObjectTest.java @@ -1,4 +1,4 @@ -// Copyright 2025 The Apache Software Foundation +// Copyright 2025, 2026 The Apache Software Foundation // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. @@ -320,8 +320,8 @@ public class JSONObjectTest { JSONObject object = new JSONObject("{fred: 'flintstone'}"); - assertTrue(object.has("fred")); - assertFalse(object.has("barney")); + assertTrue(object.containsKey("fred")); + assertFalse(object.containsKey("barney")); } @Test @@ -456,7 +456,12 @@ public class JSONObjectTest { return Stream.of( Arguments.of(null, "\"\"", "null is empty string"), Arguments.of("", "\"\"", "empty string is empty string"), - Arguments.of("\"/\b\t\n\f\r\u2001/a</", "\"\\\"/\\b\\t\\n\\f\\r\\u2001/a<\\/\"", "special characters") + Arguments.of("\"/\b\t\n\f\r\u2001/a</", "\"\\\"/\\b\\t\\n\\f\\r\\u2001/a<\\/\"", "special characters"), + Arguments.of( + " \u0080\u009f\u00a0\u1fff\u2000\u20ff\u2100", + "\"\\u001f \\u0080\\u009f\u00a0\u1fff\\u2000\\u20ff\u2100\"", + "escape range boundaries: 0x1F/0x20, 0x7F/0x80/0x9F/0xA0, 0x1FFF/0x2000/0x20FF/0x2100" + ) ); } @@ -888,4 +893,4 @@ public class JSONObjectTest { assertEquals(defaultValue, value); } -} \ No newline at end of file +}
