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Wast is a high-performance Java toolset library package that includes JSON, YAML, CSV, HttpClient, JDBC and EL engines
package io.github.wycst.wast.yaml;
import java.util.List;
/**
* @Author: wangy
* @Date: 2022/5/22 9:28
* @Description:
*/
class YamlParser extends YamlGeneral {
// yaml source
protected char[] source;
// current pos
private int pos;
// 行数
private int lineNum;
// 根缩进数
private int rootIndent = -1;
// document split support
protected void parseYamlRoot(int i) {
}
/**
* 解析yaml核心实现
*
* @param yamlNodes
* @param offset
* @param toIndex
*/
protected void parseNodes(List yamlNodes, int offset, int toIndex) {
char ch, prevCh = '\0';
for (int i = offset; i < toIndex; i++) {
String key = null, value = null, anchorKey = null, referenceKey = null;
boolean isEmpty = false, leaf = false, textBlock = false, arrayToken = false;
int j = i, splitIndex = -1, valueType = 0;
Object typeOfValue = null;
// 1、解析缩进（已去除后置空白字符不用考虑数组越界问题,必然会出现非空白字符终止循环）
while ((source[i]) == SPACE_CHAR) {
i++;
}
// 当前line的缩进空白数
int indent = i - j;
ch = source[i];
/** 是否注释开头 */
if (ch == '#') {
// 去除注释行
i++;
while (!isNewLineChar(source[i])) {
i++;
}
continue;
} else if (isNewLineChar(ch)) {
continue;
}
// create node
// YamlNode yamlNode = new YamlNode();
// begin from 0
int lineIndex = this.lineNum;
if(rootIndent == -1) {
rootIndent = indent;
} else {
if(indent < rootIndent) {
throw new YamlParseException("indent value " + indent + " error, cannot less then the root indent " + rootIndent + ", at lineNum " + (lineNum + 1));
}
}
// 数组（- -）/分片（---）
if (ch == '-') {
char append = source[i + 1];
boolean isAppendSpaceChar = append == SPACE_CHAR;
if (isAppendSpaceChar || isNewLineChar(append)) {
// 第一层数组token标记
arrayToken = true;
i++;
// 紧跟空格或者换行符则解析为数组token
// 允许同一行出现多个-，每一个-代表一层数组，中间用空格分隔，需要解析每个-的缩进
// 多个节点的lineNum相同
// 当查找的下一个字符不是-或者append不是空格或者回车
// 循环条件
j = i;
while (isAppendSpaceChar) {
while ((ch = source[++j]) == SPACE_CHAR) ;
if (ch == '-') {
append = source[j + 1];
isAppendSpaceChar = append == SPACE_CHAR;
if (isAppendSpaceChar || isNewLineChar(append)) {
// 上一层数组token添加到list中，并更新indent
addYamlNode(yamlNodes, indent, lineIndex, null, null, valueType, null, false, false, true, anchorKey, referenceKey);
// 更新下一个indent
indent += j - i + 1;
j++;
i = j;
} else {
break;
}
} else {
break;
}
}
// 查找是否存在键值分隔符（: ）
// 如果存在分隔符，解析并将i定位到指定位置
// todo 优化点： 如果不存在分隔符，会将指针回退到开始位置（- 后面）重新解析集合的value(此处会存在性能损失)
int n = j - i;
j = i;
prevCh = '\0';
while (!isNewLineChar(ch = source[j])) {
if (ch != SPACE_CHAR || prevCh != SPLIT_CHAR) {
prevCh = ch;
j++;
continue;
}
splitIndex = j;
break;
}
if (splitIndex > -1) {
// key值
key = new String(source, i, j - i - 1).trim();
if (key.length() == 0) {
throw new UnsupportedOperationException("empty key before ': ' at line " + ++lineNum);
}
// 添加Node
addYamlNode(yamlNodes, indent, lineIndex, null, null, valueType, null, false, false, true, anchorKey, referenceKey);
// 更新indent
indent += n + 1;
// 下一个键值对节点解析
arrayToken = false;
// 并将i定位到指定位置j
i = j;
} else {
// 遇到\n回退lineNum值
if (ch == '\n') {
lineNum--;
}
}
} else {
// 判断是否结束标志： ---
if (append == '-' && source[i + 2] == '-') {
int k = i + 2;
while ((ch = source[++k]) == SPACE_CHAR) ;
if (isNewLineChar(ch)) {
// --- yaml文档结束
// 解析下一个文档
parseYamlRoot(k + 1);
break;
}
}
}
}
j = i;
// 2、解析分隔符(: )等信息
// 循环终止标记
boolean breakOutLoop = false;
while (!isNewLineChar(ch = source[i])) {
if (!arrayToken && splitIndex == -1) {
// 键值对解析
if (ch != SPACE_CHAR || prevCh != SPLIT_CHAR) {
prevCh = ch;
i++;
continue;
}
// 空格位置作为分隔符
splitIndex = i;
// 计算key值
key = new String(source, j, i - j - 1).trim();
if (key.length() == 0) {
throw new UnsupportedOperationException("empty key before ': ' at line " + ++lineNum);
}
}
// 查找value(去除value前空白)
while ((ch = source[++i]) == SPACE_CHAR) ;
j = i;
if (ch == '#') {
// 注释内容
while (!isNewLineChar(source[i])) {
i++;
}
// 分隔符后面如果紧跟注释token则行值为空
value = null;
break;
} else if (ch == '\'' || ch == '"') {
// 判断是否以'或者"开始,匹配结束的'或者"，匹配成功后紧跟的字符： 空格，#， 回车符
// 否则匹配发现是否存在空格+#,如果发现代表后面的字符都为注释
leaf = true;
valueType = 1;
char strChar = ch;
i++;
j = i;
prevCh = '\'';
boolean matchEndFlag = false;
while (!isNewLineChar(ch = source[i])) {
// yaml不考虑转移字符\\
if (ch == strChar/* && prevCh != '\\'*/) {
matchEndFlag = true;
// 匹配到结束字符
value = new String(source, j, i - j);
// 去除value后的空白
while ((ch = source[++i]) == SPACE_CHAR) ;
if (ch == '#') {
i++;
while (!isNewLineChar(source[i])) {
i++;
}
break;
} else if (isNewLineChar(ch)) {
// do nothing
break;
} else {
throw new RuntimeException("未期望的字符 '" + ch + "', lineNum " + lineNum);
}
}
i++;
}
if (!matchEndFlag) {
throw new RuntimeException("未找到结束字符 " + strChar + " , index " + i);
} else {
break;
}
} else if (ch == '|' || ch == '>') {
leaf = true;
valueType = 1;
// > 用空格替换换行符
// 注意和snakeyaml库包解析有出入
boolean replaceAsSpace = ch == '>';
// | |+ |-
// 匹配段落，匹配的结束标志为换行符+当前缩进数量的空格+紧跟非空格字符
textBlock = true;
// 匹配到下一个line的indent = ${textBlockIndent} 缩进
// 查找第一行非空行作为baseTextIndent，每行的字符串内容为需要减去baseTextIndent个空格
int blockType = 0;
// 判断下一个字符
ch = source[++i];
if (ch == '+') {
blockType = 1;
i++;
} else if (ch == '-') {
blockType = 2;
i++;
}
char appendChar = replaceAsSpace ? SPACE_CHAR : '\n';
// 去除空白
while ((ch = source[i]) == SPACE_CHAR) {
i++;
}
// 第一行的注释非内容区和换行
// if (ch == '#') {
// // 注释处理
// i++;
// while (source[i++] != '\n') ;
// lineNum++;
// } else if (ch == '\n') {
// // 如果是换行符
// i++;
// lineNum++;
// } else {
// throw new RuntimeException("expected chomping or indentation indicators, but found " + ch + " in 'string', line " + lineNum + ", column n:");
// }
switch (ch) {
case '#': {
// 注释处理
i++;
while (source[i++] != '\n') ;
lineNum++;
break;
}
case '\r': {
i++;
}
case '\n': {
i++;
lineNum++;
break;
}
default:
throw new RuntimeException("expected chomping or indentation indicators, but found " + ch + " in 'string', line " + (lineNum + 1) + ", column n:");
}
// 添加到line
YamlLine blockYamlNode = addYamlNode(yamlNodes, indent, lineIndex, key, value, valueType, typeOfValue, leaf, textBlock, arrayToken, anchorKey, referenceKey);
// 解析紧跟的文本内容直到文本块结束
StringBuilder blockValue = new StringBuilder();
// 最小文本缩进
int minTextIndent = indent;
j = i;
// 去除文本块标记开始的空行，以便获取第一个非空行缩进信息
do {
// 防越界处理
if (i >= toIndex) {
blockYamlNode.value = getBlockValue(blockValue, blockType, appendChar);
blockYamlNode.blockType = blockType;
breakOutLoop = true;
break;
}
if ((ch = source[i]) != SPACE_CHAR && !isNewLineChar(ch)) {
break;
}
i++;
if (ch != SPACE_CHAR) {
// 如果是换行符（空行）
blockValue.append(appendChar);
j = i;
}
} while (true);
// 当前line的缩进空白数
int textIndent = i - j;
// 如果缩进数不大于minTextIndent则代表文本块结束
if (textIndent <= minTextIndent) {
blockYamlNode.value = getBlockValue(blockValue, blockType, appendChar);
blockYamlNode.blockType = blockType;
// 回滚当前行
i = j;
parseNodes(yamlNodes, i, toIndex);
breakOutLoop = true;
break;
}
// 第一行的缩进为基础缩进
int baseTextIndent = textIndent;
// 防越界
while (i < toIndex) {
i++;
// 遇到换行终止
// \r\n需要剔除\r
while (!isNewLineChar(ch = source[i])) {
i++;
}
int off = j + baseTextIndent;
blockValue.append(source, off, i - off);
blockValue.append(appendChar);
// 遇到\r处理
if(ch == '\r') {
i++;
lineNum++;
}
/** 如果读取到内容结束 */
if (i == toIndex - 1) {
blockYamlNode.value = getBlockValue(blockValue, blockType, appendChar);
blockYamlNode.blockType = blockType;
breakOutLoop = true;
break;
}
j = i + 1;
// 去除空行或者空白字符，遇到非空字符终止，计算缩进信息
while ((ch = source[++i]) == SPACE_CHAR || isNewLineChar(ch)) {
if (ch != SPACE_CHAR) {
// 空行
blockValue.append(appendChar);
if(ch == '\r') {
i++;
lineNum++;
}
j = i + 1;
}
if (i == toIndex - 1) {
blockYamlNode.value = getBlockValue(blockValue, blockType, appendChar);
blockYamlNode.blockType = blockType;
breakOutLoop = true;
break;
}
}
// 新的一行缩进
textIndent = i - j;
// 文本块的每行字符串内容的缩进必须大于indent（minTextIndent），且大于或者等于baseTextIndent
// 否则为文本块结束标记
if (textIndent <= minTextIndent) {
// 文本块结束
blockYamlNode.value = getBlockValue(blockValue, blockType, appendChar);
blockYamlNode.blockType = blockType;
i = j;
parseNodes(yamlNodes, i, toIndex);
breakOutLoop = true;
break;
} else {
if (textIndent < baseTextIndent) {
throw new YamlParseException("indent error, lineNum " + lineNum);
}
}
}
if (breakOutLoop) {
break;
}
} else if (ch == '&') {
// 锚点支持紧跟'合法'字符(暂定不能为空格和换行符)
if (anchorKey == null) {
char anchorAppend = source[i + 1];
if (anchorAppend == SPACE_CHAR || isNewLineChar(anchorAppend)) {
throw new YamlParseException("anchor token '&' cannot be followed by ' ' and '\\n', line " + lineNum);
}
i++;
j = i;
while ((ch = source[++i]) != SPACE_CHAR && !isNewLineChar(ch)) ;
// 锚点key
anchorKey = new String(source, j, i - j).trim();
}
} else if (ch == '*') {
// 锚点引用
char referenceAppend = source[i + 1];
if (referenceAppend == SPACE_CHAR || isNewLineChar(referenceAppend)) {
throw new YamlParseException("reference token '*' cannot be followed by ' ' and '\\n', line " + lineNum);
}
i++;
j = i;
while ((ch = source[++i]) != SPACE_CHAR && !isNewLineChar(ch)) ;
// 引用key
referenceKey = new String(source, j, i - j).trim();
// 如果后面是空格校验是否是注释或者换行，否则抛出异常
if (ch == SPACE_CHAR) {
while ((ch = source[++i]) == SPACE_CHAR) ;
if (ch != '#' && !isNewLineChar(ch)) {
throw new YamlParseException("reference token '*" + referenceKey + "' cannot be followed by any value character, line " + lineNum);
}
// 清除注释
if (ch == '#') {
// 注释内容
i++;
while (!isNewLineChar(source[i])) {
i++;
}
}
}
} else if (ch == '!') {
if (valueType == 0) {
// 类型转化枚举
char typeAppend = source[i + 1];
if (typeAppend != '!') {
valueType = 1;
continue;
// throw new YamlParseException("'!' must be followed by '!' but found '" + typeAppend + "', line " + lineNum);
}
i++;
i++;
j = i;
while ((ch = source[++i]) != SPACE_CHAR && !isNewLineChar(ch)) ;
String typeName;
if (ch == SPACE_CHAR) {
typeName = new String(source, j, i - j).trim();
if (typeValues.containsKey(typeName)) {
valueType = typeValues.get(typeName);
} else {
throw new YamlParseException("Mandatory type '!!" + typeName + "' is not supported, line " + lineNum);
}
} else {
throw new YamlParseException("token '!!' must be followed by one type such as int, str, bool ..., but empty, line " + lineNum);
}
}
} else {
boolean json = ch == '{' || ch == '[';
char pv = '\0';
int commentIndex = -1;
while (!isNewLineChar(ch = source[i])) {
if (commentIndex == -1 && pv == SPACE_CHAR && ch == '#') {
commentIndex = i;
}
i++;
pv = ch;
}
value = new String(source, j, (commentIndex > -1 ? commentIndex : i) - j).trim();
leaf = value.length() > 0;
if (json) {
// 解析JSON数据
try {
typeOfValue = YamlJSON.parse(value);
} catch (YamlParseException exception) {
String message = exception.getMessage();
message += ", at lineNum " + (lineNum + 1);
throw new YamlParseException(message, exception);
}
}
break;
}
}
if (breakOutLoop) {
break;
}
if (!arrayToken && splitIndex == -1) {
if (prevCh == SPLIT_CHAR) {
key = new String(source, j, i - j - 1).trim();
leaf = false;
} else {
throw new YamlParseException("Separator ': ' not found in syntax, at line " + ++lineNum);
}
}
// 空行
if (isEmpty) continue;
// 添加到list
addYamlNode(yamlNodes, indent, lineIndex, key, value, valueType, typeOfValue, leaf, textBlock, arrayToken, anchorKey, referenceKey);
}
}
/**
* 根据块类型去除尾部换行或者空格
*/
private String getBlockValue(StringBuilder blockValue, int blockType, char target) {
if (blockType == 1) {
// (|+ or >+)原样输出
return blockValue.toString();
}
int len = blockValue.length();
int i = len;
while (i > 0 && blockValue.charAt(i - 1) == target) {
i--;
}
// blockType == 0(| or >) 时保留一行空行（或者空格）
// blockType == 2(|- or >-) 清除所有空行（或者空格）
int newLen = (blockType == 2 || i == len) ? i : i + 1;
blockValue.setLength(newLen);
return blockValue.toString();
}
private YamlNode addYamlNode(List yamlNodes, int indent, int lineNum, String key, String value, int valueType, Object typeOfValue, boolean leaf, boolean textBlock, boolean arrayToken, String anchorKey, String referenceKey) {
YamlNode yamlNode = new YamlNode();
yamlNode.indent = indent;
yamlNode.lineNum = lineNum;
yamlNode.textBlock = textBlock;
yamlNode.key = key;
yamlNode.value = value;
yamlNode.valueType = valueType;
yamlNode.typeOfValue = typeOfValue;
yamlNode.leaf = leaf;
yamlNode.arrayToken = arrayToken;
yamlNode.anchorKey = anchorKey;
yamlNode.referenceKey = referenceKey;
yamlNodes.add(yamlNode);
return yamlNode;
}
/**
* 如果是最后一个字符判定为true
*/
private boolean isNewLineChar(char ch) {
if (ch == '\n') {
lineNum++;
return true;
}
return ch == '\r';
}
}