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/**
* Copyright 2019-2021, Zhichun Wu
*
* 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 ru.yandex.clickhouse.jdbcbridge.core;
import java.util.Objects;
import io.vertx.core.MultiMap;
import io.vertx.core.http.HttpServerRequest;
import io.vertx.ext.web.RoutingContext;
import static ru.yandex.clickhouse.jdbcbridge.core.Utils.EMPTY_STRING;
/**
* This class extracts key information like connection string, schema, query,
* and parameters etc. from http request.
*
* @since 2.0
*/
public class QueryParser {
private static final String PARAM_CONNECTION_STRING = "connection_string";
private static final String PARAM_SCHEMA = "schema";
private static final String PARAM_TABLE = "table";
// If it is set to true, external table functions will implicitly use Nullable
// type if needed.
// Otherwise NULLs will be substituted with default values.
// Currently supported only for 'mysql' table function.
private static final String PARAM_EXT_TABLE_USE_NULLS = "external_table_functions_use_nulls";
private static final String PARAM_COLUMNS = "columns";
private static final String PARAM_SAMPLE_BLOCK = "sample_block";
private static final String PARAM_QUERY = "query";
private static final String PARAM_DB_NAME = "db_name";
private static final String PARAM_TABLE_NAME = "table_name";
private static final String PARAM_FORMAT_NAME = "format_name";
private static final String KEYWORD_FROM = "FROM";
private static final String EXPR_QUERY = PARAM_QUERY + "=";
private static final String EXPR_FROM = " " + KEYWORD_FROM + " ";
private static final String EXPR_SAMPLE_BLOCK = "sample_block=";
private static final String FORMAT_ROW_BINARY = "RowBinary";
private static final String SINGLE_LINE_COMMENT = "--";
private static final String MULTILINE_COMMENT_BEGIN = "/*";
private static final String MULTILINE_COMMENT_END = "*/";
private static final String DOUBLE_QUOTES_STRING = "''";
private static final String ESCAPED_QUOTE_STRING = "\\'";
private static final String ESCAPED_BACKTICK_STRING = "\\`";
private final String uri;
private final String schema;
private final String table;
private final String columnsInfo;
private final String inputFormat;
private final boolean useNull;
private final StreamOptions options;
private String normalizedSchema = null;
private String normalizedQuery = null;
private QueryParameters queryParams = null;
private TableDefinition columns = null;
protected QueryParser(String uri, String schema, String table, String columnsInfo, String inputFormat,
String useNull, MultiMap params) {
this.uri = uri;
this.schema = schema;
this.table = table;
this.columnsInfo = columnsInfo;
this.inputFormat = inputFormat;
this.useNull = Boolean.parseBoolean(useNull);
this.options = new StreamOptions(params);
}
public String getConnectionString() {
return this.uri;
}
public String getRawQuery() {
return this.table;
}
public String getRawSchema() {
return this.schema;
}
public String extractTable(String normalizedQuery) {
String tableName = extractTableName(normalizedQuery);
if (tableName == null) {
tableName = extractTableName(this.table);
}
return tableName == null ? this.table : tableName;
}
public boolean usingRowBinaryInput() {
return FORMAT_ROW_BINARY.equals(this.inputFormat);
}
public StreamOptions getStreamOptions() {
return this.options;
}
public TableDefinition getTable() {
if (this.columns == null) {
this.columns = TableDefinition.fromString(this.columnsInfo);
}
return this.columns;
}
public boolean useNullable() {
return this.useNull;
}
public QueryParameters getQueryParameters() {
if (this.queryParams == null) {
this.queryParams = new QueryParameters(this.uri);
}
return this.queryParams;
}
public String getNormalizedSchema() {
if (this.normalizedSchema == null) {
this.normalizedSchema = Utils.applyVariables(Utils.unescapeQuotes(this.schema),
this.getQueryParameters().asVariables());
}
return this.normalizedSchema;
}
public String getNormalizedQuery() {
if (this.normalizedQuery == null) {
this.normalizedQuery = Utils.applyVariables(normalizeQuery(this.table),
this.getQueryParameters().asVariables());
}
return this.normalizedQuery;
}
static String extractSchemaName(String query) {
String schema = EMPTY_STRING;
if (query == null || query.isEmpty()) {
return schema;
}
int len = query.length();
int index = query.indexOf(EXPR_FROM);
if (index > 0 && len > (index = index + EXPR_FROM.length())) {
// assume quote is just one character and it always exists
char quote = query.charAt(index++);
// FIXME what if schema contains '.'?
int dotIndex = query.indexOf('.', index);
if (dotIndex > index && len > dotIndex && query.charAt(dotIndex - 1) == quote
&& query.charAt(dotIndex + 1) == quote) { // has schema
schema = query.substring(index, dotIndex - 1);
}
}
return schema;
}
static String extractTableName(String query) {
if (query == null || query.isEmpty()) {
return query;
}
String table = query;
int len = query.length();
int index = -1;
boolean quoteStarted = false;
for (int i = 0; i < len; i++) {
String nextTwo = query.substring(i, Math.min(i + 2, len));
if (SINGLE_LINE_COMMENT.equals(nextTwo)) {
int newIdx = query.indexOf("\n", i);
i = newIdx != -1 ? Math.max(i, newIdx) : len;
} else if (MULTILINE_COMMENT_BEGIN.equals(nextTwo)) {
int newIdx = query.indexOf(MULTILINE_COMMENT_END, i);
i = newIdx != -1 ? newIdx + 1 : len;
} else if (DOUBLE_QUOTES_STRING.equals(nextTwo) || ESCAPED_QUOTE_STRING.equals(nextTwo)
|| ESCAPED_BACKTICK_STRING.equals(nextTwo)) {
// ignore escaped single quote
i += nextTwo.length() - 1;
} else if (nextTwo.charAt(0) == '\'') {
if (quoteStarted = !quoteStarted) {
i += nextTwo.length() - 1;
}
} else if (!quoteStarted) {
char ch = nextTwo.charAt(0);
if (index > 0 && ch == '(') {
index = 0;
} else if (Character.isWhitespace(ch)) {
if (index > 0) {
if (index + 1 == i) {
index = i;
} else {
table = query.substring(index + 1, i);
index = -1;
break;
}
} else {
index = i + KEYWORD_FROM.length() + 1;
if (index < len) {
String str = query.substring(i + 1, index);
if (KEYWORD_FROM.equalsIgnoreCase(str) && Character.isWhitespace(query.charAt(index))) {
i = index;
} else {
index = 0;
}
} else {
break;
}
}
} else {
continue;
}
}
}
if (index > 0) {
table = query.substring(index + 1);
} else if (index != -1) {
table = null;
}
return table;
}
public static String extractConnectionString(RoutingContext ctx, Repository resolver) {
HttpServerRequest req = Objects.requireNonNull(ctx).request();
return Objects.requireNonNull(resolver).resolve(req.getParam(PARAM_CONNECTION_STRING));
}
public static QueryParser fromRequest(RoutingContext ctx, Repository resolver) {
return fromRequest(ctx, resolver, false);
}
public static QueryParser fromRequest(RoutingContext ctx, Repository resolver, boolean forWrite) {
HttpServerRequest req = Objects.requireNonNull(ctx).request();
final QueryParser query;
String uri = Objects.requireNonNull(resolver).resolve(req.getParam(PARAM_CONNECTION_STRING));
if (forWrite) {
String columns = req.getParam(PARAM_SAMPLE_BLOCK);
if (columns == null) {
columns = req.getParam(PARAM_COLUMNS);
}
query = new QueryParser(uri, req.getParam(PARAM_DB_NAME), req.getParam(PARAM_TABLE_NAME), columns,
req.getParam(PARAM_FORMAT_NAME), null, null);
} else {
String schema = req.getParam(PARAM_SCHEMA);
String table = req.getParam(PARAM_TABLE);
String columns = null;
// since PR #23215(merged into 21.5), columns parameter is removed and it's
// replaced by sample_block in request_body
if (table == null) {
table = ctx.getBodyAsString();
if (table == null) {
table = EMPTY_STRING;
} else {
int len = EXPR_SAMPLE_BLOCK.length();
int index = table.indexOf('&');
if (table.startsWith(EXPR_SAMPLE_BLOCK) && index > len) {
columns = unescape(table.substring(len, index));
table = unescape(table.substring(index + 1));
}
table = table.startsWith(EXPR_QUERY) ? table.substring(EXPR_QUERY.length()) : table;
}
}
if (columns == null) {
columns = req.getParam(PARAM_SAMPLE_BLOCK);
if (columns == null) {
columns = req.getParam(PARAM_COLUMNS);
}
}
if (schema == null) {
if (table.isEmpty()) {
schema = EMPTY_STRING;
} else {
schema = extractSchemaName(table);
}
}
query = new QueryParser(uri, schema, table, columns, null, req.getParam(PARAM_EXT_TABLE_USE_NULLS),
req.params());
}
return query;
}
// https://github.com/ClickHouse/ClickHouse/blob/v21.5.5.12-stable/src/Common/escapeForFileName.cpp#L33
static String unescape(String str) {
StringBuilder builder = new StringBuilder();
for (int i = 0, len = str.length(); i < len; i++) {
char ch = str.charAt(i);
if (ch == '%' && i + 2 < len) {
ch = (char) Integer.parseInt(str.substring(i + 1, i + 3), 16);
i = i + 2;
}
builder.append(ch);
}
return builder.toString();
}
static String normalizeQuery(String query) {
String normalizedQuery = Objects.requireNonNull(query);
// since we checked if this could be a named query before calling this method,
// we know the extracted query will be either a table name or an adhoc query
String extractedQuery = null;
int len = query.length();
int index = query.indexOf(EXPR_FROM);
if (index > 0 && len > (index = index + EXPR_FROM.length())) {
// assume quote is just one character and it always exists
char quote = query.charAt(index++);
boolean isQuote = quote == '"' || quote == '`';
int dotIndex = isQuote ? query.indexOf('.', index) : -1;
if (dotIndex > index && query.charAt(dotIndex - 1) == quote && query.charAt(dotIndex + 1) == quote) { // has
// schema
dotIndex += 2;
} else if (isQuote) {
dotIndex = index;
} else {
dotIndex = len;
}
boolean quoteStarted = false;
for (int i = dotIndex; i < len; i++) {
String nextTwo = query.substring(i, Math.min(i + 2, len));
if (SINGLE_LINE_COMMENT.equals(nextTwo)) {
int newIdx = query.indexOf("\n", i);
i = newIdx != -1 ? Math.max(i, newIdx) : len;
} else if (MULTILINE_COMMENT_BEGIN.equals(nextTwo)) {
int newIdx = query.indexOf(MULTILINE_COMMENT_END, i);
i = newIdx != -1 ? newIdx + 1 : len;
} else if (DOUBLE_QUOTES_STRING.equals(nextTwo) || ESCAPED_QUOTE_STRING.equals(nextTwo)
|| ESCAPED_BACKTICK_STRING.equals(nextTwo)) {
// ignore escaped single quote
i += nextTwo.length() - 1;
} else if (nextTwo.charAt(0) == '\'') {
if (quoteStarted = !quoteStarted) {
i += nextTwo.length() - 1;
}
} else if (!quoteStarted && nextTwo.charAt(0) == quote) {
extractedQuery = query.substring(dotIndex, i);
break;
}
}
}
normalizedQuery = extractedQuery != null ? extractedQuery.trim() : normalizedQuery.trim();
len = normalizedQuery.length();
// unescape String is mission impossible so we only considered below ones:
// \t Insert a tab in the text at this point.
// \b Insert a backspace in the text at this point.
// \n Insert a newline in the text at this point.
// \r Insert a carriage return in the text at this point.
// \f Insert a formfeed in the text at this point.
// \' Insert a single quote character in the text at this point.
// \" Insert a double quote character in the text at this point.
// \` Insert a backtick character in the text at this point.
// \\ Insert a backslash character in the text at this point.
StringBuilder builder = new StringBuilder();
for (int i = 0; i < len; i++) {
char ch = normalizedQuery.charAt(i);
if (ch == '\\' && i + 1 < len) {
char nextCh = normalizedQuery.charAt(i + 1);
switch (nextCh) {
case 't':
builder.append('\t');
i++;
break;
case 'b':
builder.append('\b');
i++;
break;
case 'n':
builder.append('\n');
i++;
break;
case 'r':
builder.append('\r');
i++;
break;
case 'f':
builder.append('\f');
i++;
break;
case '\'':
builder.append('\'');
i++;
break;
case '"':
builder.append('"');
i++;
break;
case '`':
builder.append('`');
i++;
break;
case '\\':
builder.append('\\');
i++;
break;
default:
builder.append(ch);
break;
}
} else {
builder.append(ch);
}
}
return builder.toString().trim();
}
}
