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package cc.blynk.clickhouse;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* Parser for JDBC SQL Strings
*
* Tries to extract query parameters in a way that is usable for (batched)
* prepared statements.
*/
final class PreparedStatementParser {
private static final Pattern VALUES = Pattern.compile(
"(?i)INSERT\\s+INTO\\s+.+VALUES\\s*\\(",
Pattern.MULTILINE | Pattern.DOTALL);
private final List> parameters;
private final List parts;
private boolean valuesMode;
private PreparedStatementParser() {
parameters = new ArrayList<>();
parts = new ArrayList<>();
valuesMode = false;
}
static PreparedStatementParser parse(String sql) {
if (sql == null || sql.isEmpty()) {
throw new IllegalArgumentException("SQL may not be blank");
}
PreparedStatementParser parser = new PreparedStatementParser();
parser.parseSQL(sql);
return parser;
}
String[][] getParameters() {
String[][] list = new String[parameters.size()][];
int i = 0;
for (List param : parameters) {
list[i++] = param.toArray(new String[0]);
}
return list;
}
List getParts() {
return Collections.unmodifiableList(parts);
}
boolean isValuesMode() {
return valuesMode;
}
private void reset() {
parameters.clear();
parts.clear();
valuesMode = false;
}
private void parseSQL(String sql) {
reset();
List currentParamList = new ArrayList<>();
boolean afterBackSlash = false;
boolean inQuotes = false;
boolean inBackQuotes = false;
boolean inSingleLineComment = false;
boolean inMultiLineComment = false;
boolean whiteSpace = false;
Matcher matcher = VALUES.matcher(sql);
if (matcher.find()) {
valuesMode = true;
}
int currentParensLevel = 0;
int quotedStart = 0;
int partStart = 0;
for (int i = valuesMode ? matcher.end() - 1 : 0, idxStart = i, idxEnd = i; i < sql.length(); i++) {
char c = sql.charAt(i);
if (inSingleLineComment) {
if (c == '\n') {
inSingleLineComment = false;
}
} else if (inMultiLineComment) {
if (c == '*' && sql.length() > i + 1 && sql.charAt(i + 1) == '/') {
inMultiLineComment = false;
i++;
}
} else if (afterBackSlash) {
afterBackSlash = false;
} else if (c == '\\') {
afterBackSlash = true;
} else if (c == '\'' && !inBackQuotes) {
inQuotes = !inQuotes;
if (inQuotes) {
quotedStart = i;
} else if (!afterBackSlash) {
idxStart = quotedStart;
idxEnd = i + 1;
}
} else if (c == '`' && !inQuotes) {
inBackQuotes = !inBackQuotes;
} else if (!inQuotes && !inBackQuotes) {
if (c == '?') {
if (currentParensLevel > 0) {
idxStart = i;
idxEnd = i + 1;
}
if (!valuesMode) {
parts.add(sql.substring(partStart, i));
partStart = i + 1;
currentParamList.add(ClickHousePreparedStatementImpl.PARAM_MARKER);
}
} else if (c == '-' && sql.length() > i + 1 && sql.charAt(i + 1) == '-') {
inSingleLineComment = true;
i++;
} else if (c == '/' && sql.length() > i + 1 && sql.charAt(i + 1) == '*') {
inMultiLineComment = true;
i++;
} else if (c == ',') {
if (valuesMode && idxEnd > idxStart) {
currentParamList.add(typeTransformParameterValue(sql.substring(idxStart, idxEnd)));
parts.add(sql.substring(partStart, idxStart));
partStart = idxEnd;
idxStart = idxEnd = i;
}
idxStart++;
idxEnd++;
} else if (c == '(') {
currentParensLevel++;
idxStart++;
idxEnd++;
} else if (c == ')') {
currentParensLevel--;
if (valuesMode && currentParensLevel == 0) {
if (idxEnd > idxStart) {
currentParamList.add(typeTransformParameterValue(sql.substring(idxStart, idxEnd)));
parts.add(sql.substring(partStart, idxStart));
partStart = idxEnd;
idxStart = idxEnd = i;
}
if (!currentParamList.isEmpty()) {
parameters.add(currentParamList);
currentParamList = new ArrayList<>(currentParamList.size());
}
}
} else if (Character.isWhitespace(c)) {
whiteSpace = true;
} else if (currentParensLevel > 0) {
if (whiteSpace) {
idxStart = i;
idxEnd = i + 1;
} else {
idxEnd++;
}
whiteSpace = false;
}
}
}
if (!valuesMode && !currentParamList.isEmpty()) {
parameters.add(currentParamList);
}
String lastPart = sql.substring(partStart);
parts.add(lastPart);
}
private static String typeTransformParameterValue(String paramValue) {
if (paramValue == null) {
return null;
}
if (Boolean.TRUE.toString().equalsIgnoreCase(paramValue)) {
return "1";
}
if (Boolean.FALSE.toString().equalsIgnoreCase(paramValue)) {
return "0";
}
if ("NULL".equalsIgnoreCase(paramValue)) {
return "\\N";
}
return paramValue;
}
}