java/src/main/java/com/jsoniter/CodegenImplEnum.java at master · baowchen/java · GitHub

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package com.jsoniter;

import com.jsoniter.spi.ClassInfo;

import java.util.*;

class CodegenImplEnum {

public static String genEnum(ClassInfo classInfo) {

StringBuilder lines = new StringBuilder();

append(lines, "if (iter.readNull()) { return null; }");

append(lines, "com.jsoniter.spi.Slice field = com.jsoniter.CodegenAccess.readSlice(iter);");

append(lines, "switch (field.len()) {");

append(lines, renderTriTree(buildTriTree(Arrays.asList(classInfo.clazz.getEnumConstants()))));

append(lines, "}"); // end of switch

append(lines, String.format("throw iter.reportError(\"decode enum\", field + \" is not valid enum for %s\");", classInfo.clazz.getName()));

return lines.toString();

}

private static Map<Integer, Object> buildTriTree(List<Object> allConsts) {

Map<Integer, Object> trieTree = new HashMap<Integer, Object>();

for (Object e : allConsts) {

byte[] fromNameBytes = e.toString().getBytes();

Map<Byte, Object> current = (Map<Byte, Object>) trieTree.get(fromNameBytes.length);

if (current == null) {

current = new HashMap<Byte, Object>();

trieTree.put(fromNameBytes.length, current);

}

for (int i = 0; i < fromNameBytes.length - 1; i++) {

byte b = fromNameBytes[i];

Map<Byte, Object> next = (Map<Byte, Object>) current.get(b);

if (next == null) {

next = new HashMap<Byte, Object>();

current.put(b, next);

}

current = next;

}

current.put(fromNameBytes[fromNameBytes.length - 1], e);

}

return trieTree;

}

private static String renderTriTree(Map<Integer, Object> trieTree) {

StringBuilder switchBody = new StringBuilder();

for (Map.Entry<Integer, Object> entry : trieTree.entrySet()) {

Integer len = entry.getKey();

append(switchBody, "case " + len + ": ");

Map<Byte, Object> current = (Map<Byte, Object>) entry.getValue();

addFieldDispatch(switchBody, len, 0, current, new ArrayList<Byte>());

append(switchBody, "break;");

}

return switchBody.toString();

}

private static void addFieldDispatch(

StringBuilder lines, int len, int i, Map<Byte, Object> current, List<Byte> bytesToCompare) {

for (Map.Entry<Byte, Object> entry : current.entrySet()) {

Byte b = entry.getKey();

if (i == len - 1) {

append(lines, "if (");

for (int j = 0; j < bytesToCompare.size(); j++) {

Byte a = bytesToCompare.get(j);

append(lines, String.format("field.at(%d)==%s && ", i - bytesToCompare.size() + j, a));

}

append(lines, String.format("field.at(%d)==%s", i, b));

append(lines, ") {");

Object e = entry.getValue();

append(lines, String.format("return %s.%s;", e.getClass().getName(), e.toString()));

append(lines, "}");

continue;

}

Map<Byte, Object> next = (Map<Byte, Object>) entry.getValue();

if (next.size() == 1) {

ArrayList<Byte> nextBytesToCompare = new ArrayList<Byte>(bytesToCompare);

nextBytesToCompare.add(b);

addFieldDispatch(lines, len, i + 1, next, nextBytesToCompare);

continue;

}

append(lines, "if (");

for (int j = 0; j < bytesToCompare.size(); j++) {

Byte a = bytesToCompare.get(j);

append(lines, String.format("field.at(%d)==%s && ", i - bytesToCompare.size() + j, a));

}

append(lines, String.format("field.at(%d)==%s", i, b));

append(lines, ") {");

addFieldDispatch(lines, len, i + 1, next, new ArrayList<Byte>());

append(lines, "}");

}

private static void append(StringBuilder lines, String str) {

lines.append(str);

lines.append("\n");

}

java/src/main/java/com/jsoniter/CodegenImplEnum.java at master · baowchen/java · GitHub

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