use WriteBuffer in formatAST(...)

programs/client/Client.cpp

@@ -54,6 +54,7 @@
 #include <IO/WriteHelpers.h>
 #include <IO/Operators.h>
 #include <IO/UseSSL.h>
+#include <IO/WriteBufferFromOStream.h>
 #include <DataStreams/AsynchronousBlockInputStream.h>
 #include <DataStreams/AddingDefaultsBlockInputStream.h>
 #include <DataStreams/InternalTextLogsRowOutputStream.h>
@@ -1529,7 +1530,8 @@ private:
         if (is_interactive)
         {
             std::cout << std::endl;
-            formatAST(*res, std::cout);
+            WriteBufferFromOStream res_buf(std::cout, 4096);
+            formatAST(*res, res_buf);
             std::cout << std::endl << std::endl;
         }
 

programs/client/QueryFuzzer.cpp

@@ -8,6 +8,7 @@
 #include <Core/Types.h>
 #include <IO/Operators.h>
 #include <IO/UseSSL.h>
+#include <IO/WriteBufferFromOStream.h>
 #include <Parsers/ASTExpressionList.h>
 #include <Parsers/ASTFunction.h>
 #include <Parsers/ASTIdentifier.h>
@@ -419,7 +420,8 @@ void QueryFuzzer::fuzzMain(ASTPtr & ast)
     fuzz(ast);
 
     std::cout << std::endl;
-    formatAST(*ast, std::cout, false /*highlight*/);
+    WriteBufferFromOStream ast_buf(std::cout, 4096);
+    formatAST(*ast, ast_buf, false /*highlight*/);
     std::cout << std::endl << std::endl;
 }
 

programs/format/Format.cpp

@@ -6,6 +6,7 @@
 #include <IO/ReadBufferFromFileDescriptor.h>
 #include <IO/ReadHelpers.h>
 #include <IO/WriteBufferFromFileDescriptor.h>
+#include <IO/WriteBufferFromOStream.h>
 #include <Parsers/ParserQuery.h>
 #include <Parsers/parseQuery.h>
 #include <Parsers/formatAST.h>
@@ -129,7 +130,8 @@ int mainEntryClickHouseFormat(int argc, char ** argv)
                 ASTPtr res = parseQueryAndMovePosition(parser, pos, end, "query", multiple, 0, DBMS_DEFAULT_MAX_PARSER_DEPTH);
                 if (!quiet)
                 {
-                    formatAST(*res, std::cout, hilite, oneline);
+                    WriteBufferFromOStream res_buf(std::cout, 4096);
+                    formatAST(*res, res_buf, hilite, oneline);
                     if (multiple)
                         std::cout << "\n;\n";
                     std::cout << std::endl;

programs/odbc-bridge/ColumnInfoHandler.cpp

@@ -113,16 +113,16 @@ void ODBCColumnsInfoHandler::handleRequest(Poco::Net::HTTPServerRequest & reques
 
         /// TODO Why not do SQLColumns instead?
         std::string name = schema_name.empty() ? backQuoteIfNeed(table_name) : backQuoteIfNeed(schema_name) + "." + backQuoteIfNeed(table_name);
-        std::stringstream ss;
+        WriteBufferFromOwnString buf;
         std::string input = "SELECT * FROM " + name + " WHERE 1 = 0";
         ParserQueryWithOutput parser;
         ASTPtr select = parseQuery(parser, input.data(), input.data() + input.size(), "", context_settings.max_query_size, context_settings.max_parser_depth);
 
-        IAST::FormatSettings settings(ss, true);
+        IAST::FormatSettings settings(buf, true);
         settings.always_quote_identifiers = true;
         settings.identifier_quoting_style = getQuotingStyle(hdbc);
         select->format(settings);
-        std::string query = ss.str();
+        std::string query = buf.str();
 
         LOG_TRACE(log, "Inferring structure with query '{}'", query);
 

programs/odbc-bridge/ODBCBlockOutputStream.cpp

@@ -32,12 +32,12 @@ namespace
         for (const auto & column : columns)
             query.columns->children.emplace_back(std::make_shared<ASTIdentifier>(column.name));
 
-        std::stringstream ss;
+        WriteBufferFromOwnString buf;
-        IAST::FormatSettings settings(ss, true);
+        IAST::FormatSettings settings(buf, true);
         settings.always_quote_identifiers = true;
         settings.identifier_quoting_style = quoting;
         query.IAST::format(settings);
-        return ss.str();
+        return buf.str();
     }
 
     std::string getQuestionMarks(size_t n)

src/Access/DiskAccessStorage.cpp

@@ -197,11 +197,13 @@ namespace
             boost::range::push_back(queries, InterpreterShowGrantsQuery::getAttachGrantQueries(entity));
 
         /// Serialize the list of ATTACH queries to a string.
-        std::stringstream ss;
+        WriteBufferFromOwnString buf;
-        ss.exceptions(std::ios::failbit);
         for (const ASTPtr & query : queries)
-            ss << *query << ";\n";
+        {
-        String file_contents = std::move(ss).str();
+            formatAST(*query, buf, false, true);
+            buf.write(";\n", 2);
+        }
+        String file_contents = buf.str();
 
         /// First we save *.tmp file and then we rename if everything's ok.
         auto tmp_file_path = std::filesystem::path{file_path}.replace_extension(".tmp");

src/Databases/DatabaseOnDisk.cpp

@@ -94,10 +94,9 @@ String getObjectDefinitionFromCreateQuery(const ASTPtr & query)
 
     if (!create)
     {
-        std::ostringstream query_stream;
+        WriteBufferFromOwnString query_buf;
-        query_stream.exceptions(std::ios::failbit);
+        formatAST(*query, query_buf, true);
-        formatAST(*query, query_stream, true);
+        throw Exception(ErrorCodes::LOGICAL_ERROR, "Query '{}' is not CREATE query", query_buf.str());
-        throw Exception("Query '" + query_stream.str() + "' is not CREATE query", ErrorCodes::LOGICAL_ERROR);
     }
 
     if (!create->is_dictionary)
@@ -121,11 +120,10 @@ String getObjectDefinitionFromCreateQuery(const ASTPtr & query)
     if (create->uuid != UUIDHelpers::Nil)
         create->table = TABLE_WITH_UUID_NAME_PLACEHOLDER;
 
-    std::ostringstream statement_stream;
+    WriteBufferFromOwnString statement_buf;
-    statement_stream.exceptions(std::ios::failbit);
+    formatAST(*create, statement_buf, false);
-    formatAST(*create, statement_stream, false);
+    writeChar('\n', statement_buf);
-    statement_stream << '\n';
+    return statement_buf.str();
-    return statement_stream.str();
 }
 
 DatabaseOnDisk::DatabaseOnDisk(

src/IO/Operators.h

@@ -45,6 +45,7 @@ struct BinaryManipReadBuffer         : std::reference_wrapper<ReadBuffer> { usin
 template <typename T>     WriteBuffer & operator<< (WriteBuffer & buf, const T & x)        { writeText(x, buf);     return buf; }
 /// If you do not use the manipulators, the string is displayed without an escape, as is.
 template <> inline        WriteBuffer & operator<< (WriteBuffer & buf, const String & x)   { writeString(x, buf);   return buf; }
+template <> inline        WriteBuffer & operator<< (WriteBuffer & buf, const std::string_view & x)   { writeString(StringRef(x), buf);   return buf; }
 template <> inline        WriteBuffer & operator<< (WriteBuffer & buf, const char & x)     { writeChar(x, buf);     return buf; }
 template <> inline        WriteBuffer & operator<< (WriteBuffer & buf, const pcg32_fast & x) { PcgSerializer::serializePcg32(x, buf); return buf; }
 

src/IO/WriteHelpers.h

@@ -271,6 +271,11 @@ inline void writeString(const StringRef & ref, WriteBuffer & buf)
     writeString(ref.data, ref.size, buf);
 }
 
+//inline void writeString(const std::string_view & view, WriteBuffer & buf)
+//{
+//    writeString(view.data(), view.size(), buf);
+//}
+
 
 /** Writes a C-string without creating a temporary object. If the string is a literal, then `strlen` is executed at the compilation stage.
   * Use when the string is a literal.

src/Interpreters/AddDefaultDatabaseVisitor.h

@@ -25,7 +25,7 @@ class AddDefaultDatabaseVisitor
 {
 public:
     explicit AddDefaultDatabaseVisitor(
-        const String & database_name_, bool only_replace_current_database_function_ = false, std::ostream * ostr_ = nullptr)
+        const String & database_name_, bool only_replace_current_database_function_ = false, WriteBuffer * ostr_ = nullptr)
         : database_name(database_name_)
         , only_replace_current_database_function(only_replace_current_database_function_)
         , visit_depth(0)
@@ -66,7 +66,7 @@ private:
     const String database_name;
     bool only_replace_current_database_function = false;
     mutable size_t visit_depth;
-    std::ostream * ostr;
+    WriteBuffer * ostr;
 
     void visit(ASTSelectWithUnionQuery & select, ASTPtr &) const
     {

src/Interpreters/ClusterProxy/SelectStreamFactory.cpp

@@ -106,10 +106,9 @@ String formattedAST(const ASTPtr & ast)
 {
     if (!ast)
         return {};
-    std::stringstream ss;
+    WriteBufferFromOwnString buf;
-    ss.exceptions(std::ios::failbit);
+    formatAST(*ast, buf, false, true);
-    formatAST(*ast, ss, false, true);
+    return buf.str();
-    return ss.str();
 }
 
 }

src/Interpreters/InDepthNodeVisitor.h

@@ -16,7 +16,7 @@ class InDepthNodeVisitor
 public:
     using Data = typename Matcher::Data;
 
-    InDepthNodeVisitor(Data & data_, std::ostream * ostr_ = nullptr)
+    InDepthNodeVisitor(Data & data_, WriteBuffer * ostr_ = nullptr)
     :   data(data_),
         visit_depth(0),
         ostr(ostr_)
@@ -46,7 +46,7 @@ public:
 private:
     Data & data;
     size_t visit_depth;
-    std::ostream * ostr;
+    WriteBuffer * ostr;
 
     void visitChildren(T & ast)
     {

src/Interpreters/InterpreterCreateQuery.cpp

@@ -135,10 +135,7 @@ BlockIO InterpreterCreateQuery::createDatabase(ASTCreateQuery & create)
     else if ((create.columns_list && create.columns_list->indices && !create.columns_list->indices->children.empty()))
     {
         /// Currently, there are no database engines, that support any arguments.
-        std::stringstream ostr;
+        throw Exception(ErrorCodes::UNKNOWN_DATABASE_ENGINE, "Unknown database engine: {}", serializeAST(*create.storage));
-        ostr.exceptions(std::ios::failbit);
-        formatAST(*create.storage, ostr, false, false);
-        throw Exception("Unknown database engine: " + ostr.str(), ErrorCodes::UNKNOWN_DATABASE_ENGINE);
     }
 
     if (create.storage->engine->name == "Atomic")
@@ -182,11 +179,10 @@ BlockIO InterpreterCreateQuery::createDatabase(ASTCreateQuery & create)
         create.attach = true;
         create.if_not_exists = false;
 
-        std::ostringstream statement_stream;
+        WriteBufferFromOwnString statement_buf;
-        statement_stream.exceptions(std::ios::failbit);
+        formatAST(create, statement_buf, false);
-        formatAST(create, statement_stream, false);
+        writeChar('\n', statement_buf);
-        statement_stream << '\n';
+        String statement = statement_buf.str();
-        String statement = statement_stream.str();
 
         /// Exclusive flag guarantees, that database is not created right now in another thread.
         WriteBufferFromFile out(metadata_file_tmp_path, statement.size(), O_WRONLY | O_CREAT | O_EXCL);

src/Interpreters/InterpreterExplainQuery.cpp

@@ -222,15 +222,14 @@ BlockInputStreamPtr InterpreterExplainQuery::executeImpl()
     Block sample_block = getSampleBlock();
     MutableColumns res_columns = sample_block.cloneEmptyColumns();
 
-    std::stringstream ss;
+    WriteBufferFromOwnString buf;
-    ss.exceptions(std::ios::failbit);
 
     if (ast.getKind() == ASTExplainQuery::ParsedAST)
     {
         if (ast.getSettings())
             throw Exception("Settings are not supported for EXPLAIN AST query.", ErrorCodes::UNKNOWN_SETTING);
 
-        dumpAST(*ast.getExplainedQuery(), ss);
+        dumpAST(*ast.getExplainedQuery(), buf);
     }
     else if (ast.getKind() == ASTExplainQuery::AnalyzedSyntax)
     {
@@ -240,7 +239,7 @@ BlockInputStreamPtr InterpreterExplainQuery::executeImpl()
         ExplainAnalyzedSyntaxVisitor::Data data{.context = context};
         ExplainAnalyzedSyntaxVisitor(data).visit(query);
 
-        ast.getExplainedQuery()->format(IAST::FormatSettings(ss, false));
+        ast.getExplainedQuery()->format(IAST::FormatSettings(buf, false));
     }
     else if (ast.getKind() == ASTExplainQuery::QueryPlan)
     {
@@ -256,8 +255,7 @@ BlockInputStreamPtr InterpreterExplainQuery::executeImpl()
         if (settings.optimize)
             plan.optimize();
 
-        WriteBufferFromOStream buffer(ss);
+        plan.explainPlan(buf, settings.query_plan_options);
-        plan.explainPlan(buffer, settings.query_plan_options);
     }
     else if (ast.getKind() == ASTExplainQuery::QueryPipeline)
     {
@@ -271,8 +269,6 @@ BlockInputStreamPtr InterpreterExplainQuery::executeImpl()
         interpreter.buildQueryPlan(plan);
         auto pipeline = plan.buildQueryPipeline();
 
-        WriteBufferFromOStream buffer(ss);
-
         if (settings.graph)
         {
             /// Pipe holds QueryPlan, should not go out-of-scope
@@ -280,17 +276,17 @@ BlockInputStreamPtr InterpreterExplainQuery::executeImpl()
             const auto & processors = pipe.getProcessors();
 
             if (settings.compact)
-                printPipelineCompact(processors, buffer, settings.query_pipeline_options.header);
+                printPipelineCompact(processors, buf, settings.query_pipeline_options.header);
             else
-                printPipeline(processors, buffer);
+                printPipeline(processors, buf);
         }
         else
         {
-            plan.explainPipeline(buffer, settings.query_pipeline_options);
+            plan.explainPipeline(buf, settings.query_pipeline_options);
         }
     }
 
-    fillColumn(*res_columns[0], ss.str());
+    fillColumn(*res_columns[0], buf.str());
 
     return std::make_shared<OneBlockInputStream>(sample_block.cloneWithColumns(std::move(res_columns)));
 }

src/Interpreters/InterpreterShowAccessQuery.cpp

@@ -34,13 +34,12 @@ BlockInputStreamPtr InterpreterShowAccessQuery::executeImpl() const
 
     /// Build the result column.
     MutableColumnPtr column = ColumnString::create();
-    std::stringstream ss;
+    WriteBufferFromOwnString buf;
-    ss.exceptions(std::ios::failbit);
     for (const auto & query : queries)
     {
-        ss.str("");
+        buf.restart();
-        formatAST(*query, ss, false, true);
+        formatAST(*query, buf, false, true);
-        column->insert(ss.str());
+        column->insert(buf.str());
     }
 
     String desc = "ACCESS";

src/Interpreters/InterpreterShowCreateAccessEntityQuery.cpp

@@ -238,21 +238,19 @@ BlockInputStreamPtr InterpreterShowCreateAccessEntityQuery::executeImpl()
 
     /// Build the result column.
     MutableColumnPtr column = ColumnString::create();
-    std::stringstream create_query_ss;
+    WriteBufferFromOwnString create_query_buf;
-    create_query_ss.exceptions(std::ios::failbit);
     for (const auto & create_query : create_queries)
     {
-        formatAST(*create_query, create_query_ss, false, true);
+        formatAST(*create_query, create_query_buf, false, true);
-        column->insert(create_query_ss.str());
+        column->insert(create_query_buf.str());
-        create_query_ss.str("");
+        create_query_buf.restart();
     }
 
     /// Prepare description of the result column.
-    std::stringstream desc_ss;
+    WriteBufferFromOwnString desc_buf;
-    desc_ss.exceptions(std::ios::failbit);
     const auto & show_query = query_ptr->as<const ASTShowCreateAccessEntityQuery &>();
-    formatAST(show_query, desc_ss, false, true);
+    formatAST(show_query, desc_buf, false, true);
-    String desc = desc_ss.str();
+    String desc = desc_buf.str();
     String prefix = "SHOW ";
     if (startsWith(desc, prefix))
         desc = desc.substr(prefix.length()); /// `desc` always starts with "SHOW ", so we can trim this prefix.

src/Interpreters/InterpreterShowCreateQuery.cpp

@@ -78,10 +78,9 @@ BlockInputStreamPtr InterpreterShowCreateQuery::executeImpl()
         create.uuid = UUIDHelpers::Nil;
     }
 
-    std::stringstream stream;
+    WriteBufferFromOwnString buf;
-    stream.exceptions(std::ios::failbit);
+    formatAST(*create_query, buf, false, false);
-    formatAST(*create_query, stream, false, false);
+    String res = buf.str();
-    String res = stream.str();
 
     MutableColumnPtr column = ColumnString::create();
     column->insert(res);

src/Interpreters/InterpreterShowGrantsQuery.cpp

@@ -118,21 +118,19 @@ BlockInputStreamPtr InterpreterShowGrantsQuery::executeImpl()
 
     /// Build the result column.
     MutableColumnPtr column = ColumnString::create();
-    std::stringstream grant_ss;
+    WriteBufferFromOwnString grant_buf;
-    grant_ss.exceptions(std::ios::failbit);
     for (const auto & grant_query : grant_queries)
     {
-        grant_ss.str("");
+        grant_buf.restart();
-        formatAST(*grant_query, grant_ss, false, true);
+        formatAST(*grant_query, grant_buf, false, true);
-        column->insert(grant_ss.str());
+        column->insert(grant_buf.str());
     }
 
     /// Prepare description of the result column.
-    std::stringstream desc_ss;
+    WriteBufferFromOwnString desc_buf;
-    desc_ss.exceptions(std::ios::failbit);
     const auto & show_query = query_ptr->as<const ASTShowGrantsQuery &>();
-    formatAST(show_query, desc_ss, false, true);
+    formatAST(show_query, desc_buf, false, true);
-    String desc = desc_ss.str();
+    String desc = desc_buf.str();
     String prefix = "SHOW ";
     if (desc.starts_with(prefix))
         desc = desc.substr(prefix.length()); /// `desc` always starts with "SHOW ", so we can trim this prefix.

src/Interpreters/QueryAliasesVisitor.cpp

@@ -20,13 +20,12 @@ namespace ErrorCodes
 
 static String wrongAliasMessage(const ASTPtr & ast, const ASTPtr & prev_ast, const String & alias)
 {
-    std::stringstream message;
+    WriteBufferFromOwnString message;
-    message.exceptions(std::ios::failbit);
+    message << "Different expressions with the same alias " << backQuoteIfNeed(alias) << ":\n";
-    message << "Different expressions with the same alias " << backQuoteIfNeed(alias) << ":" << std::endl;
     formatAST(*ast, message, false, true);
-    message << std::endl << "and" << std::endl;
+    message << "\nand\n";
     formatAST(*prev_ast, message, false, true);
-    message << std::endl;
+    message << '\n';
     return message.str();
 }
 

src/Parsers/ASTAlterQuery.cpp

@@ -1,4 +1,5 @@
 #include <Parsers/ASTAlterQuery.h>
+#include <IO/Operators.h>
 #include <iomanip>
 #include <Common/quoteString.h>
 
@@ -246,7 +247,7 @@ void ASTAlterCommand::formatImpl(
                       << "PARTITION " << (settings.hilite ? hilite_none : "");
         partition->formatImpl(settings, state, frame);
         settings.ostr << (settings.hilite ? hilite_keyword : "")
-                      << " FROM " << (settings.hilite ? hilite_none : "") << std::quoted(from, '\'');
+                      << " FROM " << (settings.hilite ? hilite_none : "") << DB::quote << from;
     }
     else if (type == ASTAlterCommand::FREEZE_PARTITION)
     {
@@ -256,7 +257,7 @@ void ASTAlterCommand::formatImpl(
         if (!with_name.empty())
         {
             settings.ostr << " " << (settings.hilite ? hilite_keyword : "") << "WITH NAME" << (settings.hilite ? hilite_none : "")
-                          << " " << std::quoted(with_name, '\'');
+                          << " " << DB::quote << with_name;
         }
     }
     else if (type == ASTAlterCommand::FREEZE_ALL)
@@ -266,7 +267,7 @@ void ASTAlterCommand::formatImpl(
         if (!with_name.empty())
         {
             settings.ostr << " " << (settings.hilite ? hilite_keyword : "") << "WITH NAME" << (settings.hilite ? hilite_none : "")
-                          << " " << std::quoted(with_name, '\'');
+                          << " " << DB::quote << with_name;
         }
     }
     else if (type == ASTAlterCommand::DELETE)

src/Parsers/ASTAsterisk.cpp

@@ -1,5 +1,6 @@
 #include <Parsers/ASTAsterisk.h>
 #include <IO/WriteBuffer.h>
+#include <IO/Operators.h>
 
 namespace DB
 {

src/Parsers/ASTColumnDeclaration.cpp

@@ -1,5 +1,6 @@
 #include <Parsers/ASTColumnDeclaration.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTColumnsMatcher.cpp

@@ -3,6 +3,7 @@
 #include <Common/quoteString.h>
 #include <re2/re2.h>
 #include <Common/SipHash.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTColumnsTransformers.cpp

@@ -5,6 +5,7 @@
 #include <Parsers/ASTIdentifier.h>
 #include <Common/SipHash.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTConstraintDeclaration.cpp

@@ -1,5 +1,6 @@
 #include <Parsers/ASTConstraintDeclaration.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTCreateQuery.cpp

@@ -5,6 +5,7 @@
 #include <Parsers/ASTSetQuery.h>
 #include <Common/quoteString.h>
 #include <Interpreters/StorageID.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTCreateQuotaQuery.cpp

@@ -3,6 +3,7 @@
 #include <Common/quoteString.h>
 #include <Common/IntervalKind.h>
 #include <ext/range.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTCreateRoleQuery.cpp

@@ -1,6 +1,7 @@
 #include <Parsers/ASTCreateRoleQuery.h>
 #include <Parsers/ASTSettingsProfileElement.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTCreateRowPolicyQuery.cpp

@@ -6,6 +6,7 @@
 #include <ext/range.h>
 #include <boost/range/algorithm/transform.hpp>
 #include <sstream>
+#include <IO/Operators.h>
 
 
 namespace DB
@@ -62,14 +63,13 @@ namespace
     void formatForClauses(const std::vector<std::pair<ConditionType, ASTPtr>> & conditions, bool alter, const IAST::FormatSettings & settings)
     {
         std::vector<std::pair<ConditionType, String>> conditions_as_strings;
-        std::stringstream temp_sstream;
+        WriteBufferFromOwnString temp_buf;
-        temp_sstream.exceptions(std::ios::failbit);
+        IAST::FormatSettings temp_settings(temp_buf, settings);
-        IAST::FormatSettings temp_settings(temp_sstream, settings);
         for (const auto & [condition_type, condition] : conditions)
         {
             formatConditionalExpression(condition, temp_settings);
-            conditions_as_strings.emplace_back(condition_type, temp_sstream.str());
+            conditions_as_strings.emplace_back(condition_type, temp_buf.str());
-            temp_sstream.str("");
+            temp_buf.restart();
         }
 
         boost::container::flat_set<std::string_view> commands;

src/Parsers/ASTCreateSettingsProfileQuery.cpp

@@ -2,6 +2,7 @@
 #include <Parsers/ASTSettingsProfileElement.h>
 #include <Parsers/ASTRolesOrUsersSet.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTCreateUserQuery.cpp

@@ -3,6 +3,7 @@
 #include <Parsers/ASTRolesOrUsersSet.h>
 #include <Parsers/ASTSettingsProfileElement.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTDictionary.cpp

@@ -1,5 +1,6 @@
 #include <Parsers/ASTDictionary.h>
 #include <Poco/String.h>
+#include <IO/Operators.h>
 
 namespace DB
 {

src/Parsers/ASTDictionaryAttributeDeclaration.cpp

@@ -1,5 +1,6 @@
 #include <Parsers/ASTDictionaryAttributeDeclaration.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTDropAccessEntityQuery.cpp

@@ -1,6 +1,7 @@
 #include <Parsers/ASTDropAccessEntityQuery.h>
 #include <Parsers/ASTRowPolicyName.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTDropQuery.cpp

@@ -1,5 +1,6 @@
 #include <Parsers/ASTDropQuery.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTExpressionList.cpp

@@ -1,4 +1,5 @@
 #include <Parsers/ASTExpressionList.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTFunction.cpp

@@ -6,6 +6,7 @@
 #include <IO/WriteHelpers.h>
 #include <IO/WriteBufferFromString.h>
 #include <Common/SipHash.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTFunctionWithKeyValueArguments.cpp

@@ -2,6 +2,7 @@
 
 #include <Poco/String.h>
 #include <Common/SipHash.h>
+#include <IO/Operators.h>
 
 namespace DB
 {

src/Parsers/ASTGrantQuery.cpp

@@ -1,6 +1,7 @@
 #include <Parsers/ASTGrantQuery.h>
 #include <Parsers/ASTRolesOrUsersSet.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTIdentifier.cpp

@@ -5,6 +5,7 @@
 #include <Interpreters/IdentifierSemantic.h>
 #include <Interpreters/StorageID.h>
 #include <Parsers/queryToString.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTIndexDeclaration.cpp

@@ -1,5 +1,6 @@
 #include <Parsers/ASTIndexDeclaration.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTInsertQuery.cpp

@@ -3,6 +3,7 @@
 #include <Parsers/ASTFunction.h>
 #include <Common/quoteString.h>
 #include <IO/WriteHelpers.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTKillQueryQuery.cpp

@@ -1,4 +1,5 @@
 #include <Parsers/ASTKillQueryQuery.h>
+#include <IO/Operators.h>
 
 namespace DB
 {

src/Parsers/ASTLiteral.cpp

@@ -73,4 +73,9 @@ void ASTLiteral::appendColumnNameImpl(WriteBuffer & ostr) const
     }
 }
 
+void ASTLiteral::formatImplWithoutAlias(const FormatSettings & settings, IAST::FormatState &, IAST::FormatStateStacked) const
+{
+    settings.ostr << applyVisitor(FieldVisitorToString(), value);
+}
+
 }

src/Parsers/ASTLiteral.h

@@ -43,10 +43,7 @@ public:
     void updateTreeHashImpl(SipHash & hash_state) const override;
 
 protected:
-    void formatImplWithoutAlias(const FormatSettings & settings, FormatState &, FormatStateStacked) const override
+    void formatImplWithoutAlias(const FormatSettings & settings, FormatState &, FormatStateStacked) const override;
-    {
-        settings.ostr << applyVisitor(FieldVisitorToString(), value);
-    }
 
     void appendColumnNameImpl(WriteBuffer & ostr) const override;
 };

src/Parsers/ASTNameTypePair.cpp

@@ -1,5 +1,6 @@
 #include <Parsers/ASTNameTypePair.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTOptimizeQuery.cpp

@@ -1,5 +1,6 @@
 #include <Parsers/ASTOptimizeQuery.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 namespace DB
 {

src/Parsers/ASTOrderByElement.cpp

@@ -1,6 +1,7 @@
 #include <Columns/Collator.h>
 #include <Parsers/ASTOrderByElement.h>
 #include <Common/SipHash.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTPartition.cpp

@@ -1,5 +1,6 @@
 #include <Parsers/ASTPartition.h>
 #include <IO/WriteHelpers.h>
+#include <IO/Operators.h>
 
 namespace DB
 {

src/Parsers/ASTQualifiedAsterisk.cpp

@@ -1,5 +1,6 @@
 #include <Parsers/ASTQualifiedAsterisk.h>
 #include <IO/WriteHelpers.h>
+#include <IO/Operators.h>
 
 namespace DB
 {

src/Parsers/ASTQueryParameter.cpp

@@ -1,6 +1,7 @@
 #include <Parsers/ASTQueryParameter.h>
 #include <IO/WriteHelpers.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTQueryWithOnCluster.cpp

@@ -5,6 +5,7 @@
 #include <Parsers/parseIdentifierOrStringLiteral.h>
 #include <Common/typeid_cast.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTQueryWithOutput.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <Parsers/IAST.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTQueryWithTableAndOutput.cpp

@@ -1,5 +1,6 @@
 #include <Parsers/ASTQueryWithTableAndOutput.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTRenameQuery.h

@@ -4,6 +4,7 @@
 #include <Parsers/ASTQueryWithOutput.h>
 #include <Parsers/ASTQueryWithOnCluster.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTRolesOrUsersSet.cpp

@@ -1,5 +1,6 @@
 #include <Parsers/ASTRolesOrUsersSet.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTRowPolicyName.cpp

@@ -1,4 +1,5 @@
 #include <Parsers/ASTRowPolicyName.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTSampleRatio.cpp

@@ -1,4 +1,5 @@
 #include <Parsers/ASTSampleRatio.h>
+#include <IO/Operators.h>
 
 namespace DB
 {
@@ -34,5 +35,9 @@ String ASTSampleRatio::toString(Rational ratio)
         return toString(ratio.numerator) + " / " + toString(ratio.denominator);
 }
 
+void ASTSampleRatio::formatImpl(const IAST::FormatSettings & settings, IAST::FormatState &, IAST::FormatStateStacked) const
+{
+    settings.ostr << toString(ratio);
+}
 
 }

src/Parsers/ASTSampleRatio.h

@@ -35,10 +35,7 @@ public:
     static String toString(BigNum num);
     static String toString(Rational ratio);
 
-    void formatImpl(const FormatSettings & settings, FormatState &, FormatStateStacked) const override
+    void formatImpl(const FormatSettings & settings, FormatState &, FormatStateStacked) const override;
-    {
-        settings.ostr << toString(ratio);
-    }
 };
 
 }

src/Parsers/ASTSelectQuery.cpp

@@ -6,6 +6,7 @@
 #include <Parsers/ASTOrderByElement.h>
 #include <Parsers/ASTTablesInSelectQuery.h>
 #include <Interpreters/StorageID.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTSelectWithUnionQuery.cpp

@@ -1,6 +1,7 @@
 #include <Parsers/ASTSelectWithUnionQuery.h>
 #include <Parsers/ASTSelectQuery.h>
 #include <Common/typeid_cast.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTSetQuery.cpp

@@ -1,6 +1,7 @@
 #include <Parsers/ASTSetQuery.h>
 #include <Parsers/formatSettingName.h>
 #include <Common/SipHash.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTSetRoleQuery.cpp

@@ -1,6 +1,7 @@
 #include <Parsers/ASTSetRoleQuery.h>
 #include <Parsers/ASTRolesOrUsersSet.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTSettingsProfileElement.cpp

@@ -2,6 +2,7 @@
 #include <Parsers/formatSettingName.h>
 #include <Common/FieldVisitors.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTShowAccessEntitiesQuery.cpp

@@ -1,5 +1,6 @@
 #include <Parsers/ASTShowAccessEntitiesQuery.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTShowCreateAccessEntityQuery.cpp

@@ -1,6 +1,7 @@
 #include <Parsers/ASTShowCreateAccessEntityQuery.h>
 #include <Parsers/ASTRowPolicyName.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTShowGrantsQuery.cpp

@@ -1,6 +1,7 @@
 #include <Parsers/ASTShowGrantsQuery.h>
 #include <Parsers/ASTRolesOrUsersSet.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTShowTablesQuery.cpp

@@ -1,6 +1,7 @@
 #include <iomanip>
 #include <Parsers/ASTShowTablesQuery.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 namespace DB
 {
@@ -21,7 +22,7 @@ void ASTShowTablesQuery::formatLike(const FormatSettings & settings) const
             << (not_like ? " NOT" : "")
             << (case_insensitive_like ? " ILIKE " : " LIKE ")
             << (settings.hilite ? hilite_none : "")
-            << std::quoted(like, '\'');
+            << DB::quote << like;
 }
 
 void ASTShowTablesQuery::formatLimit(const FormatSettings & settings, FormatState & state, FormatStateStacked frame) const

src/Parsers/ASTSubquery.cpp

@@ -1,5 +1,6 @@
 #include <Parsers/ASTSubquery.h>
 #include <IO/WriteHelpers.h>
+#include <IO/Operators.h>
 
 namespace DB
 {

src/Parsers/ASTSystemQuery.cpp

@@ -1,6 +1,7 @@
 #include <Parsers/IAST.h>
 #include <Parsers/ASTSystemQuery.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTTTLElement.cpp

@@ -2,6 +2,7 @@
 #include <Columns/Collator.h>
 #include <Common/quoteString.h>
 #include <Parsers/ASTTTLElement.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTTablesInSelectQuery.cpp

@@ -2,6 +2,7 @@
 #include <Parsers/ASTExpressionList.h>
 #include <Parsers/ASTTablesInSelectQuery.h>
 #include <Common/SipHash.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTUseQuery.h

@@ -2,6 +2,7 @@
 
 #include <Parsers/IAST.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTUserNameWithHost.cpp

@@ -1,5 +1,6 @@
 #include <Parsers/ASTUserNameWithHost.h>
 #include <Common/quoteString.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTWithAlias.cpp

@@ -1,6 +1,7 @@
 #include <Parsers/ASTWithAlias.h>
 #include <IO/WriteBufferFromOStream.h>
 #include <IO/WriteHelpers.h>
+#include <IO/Operators.h>
 
 
 namespace DB

src/Parsers/ASTWithElement.cpp

@@ -1,4 +1,5 @@
 #include <Parsers/ASTWithElement.h>
+#include <IO/Operators.h>
 
 namespace DB
 {

src/Parsers/CommonParsers.cpp

@@ -1,6 +1,7 @@
 #include <Common/StringUtils/StringUtils.h>
 #include <Parsers/CommonParsers.h>
 #include <common/find_symbols.h>
+#include <IO/Operators.h>
 
 #include <string.h>        /// strncmp, strncasecmp
 

src/Parsers/DumpASTNode.h

@@ -3,6 +3,7 @@
 #include <sstream>
 #include <common/logger_useful.h>
 #include <Poco/Util/Application.h>
+#include <IO/Operators.h>
 
 #include <Parsers/IAST.h>
 
@@ -14,7 +15,7 @@ namespace DB
 class DumpASTNode
 {
 public:
-    DumpASTNode(const IAST & ast_, std::ostream * ostr_, size_t & depth, const char * label_ = nullptr)
+    DumpASTNode(const IAST & ast_, WriteBuffer * ostr_, size_t & depth, const char * label_ = nullptr)
         : ast(ast_),
         ostr(ostr_),
         indent(depth),
@@ -24,12 +25,12 @@ public:
         if (!ostr)
             return;
         if (label && visit_depth == 0)
-            (*ostr) << "-- " << label << std::endl;
+            (*ostr) << "-- " << label << '\n';
         ++visit_depth;
 
         (*ostr) << String(indent, ' ');
         printNode();
-        (*ostr) << std::endl;
+        (*ostr) << '\n';
     }
 
     ~DumpASTNode()
@@ -38,7 +39,7 @@ public:
             return;
         --visit_depth;
         if (label && visit_depth == 0)
-            (*ostr) << "--" << std::endl;
+            (*ostr) << "--\n";
     }
 
     template <typename T, typename U>
@@ -50,14 +51,14 @@ public:
         (*ostr) << (str_indent ? String(str_indent) : String(indent, ' '));
         (*ostr) << '(' << name << ' ' << value << ')';
         if (!str_indent)
-            (*ostr) << std::endl;
+            (*ostr) << '\n';
     }
 
     size_t & getDepth() { return visit_depth; }
 
 private:
     const IAST & ast;
-    std::ostream * ostr;
+    WriteBuffer * ostr;
     size_t indent;
     size_t & visit_depth; /// shared with children
     const char * label;
@@ -77,7 +78,7 @@ private:
     }
 };
 
-inline void dumpAST(const IAST & ast, std::ostream & ostr, DumpASTNode * parent = nullptr)
+inline void dumpAST(const IAST & ast, WriteBuffer & ostr, DumpASTNode * parent = nullptr)
 {
     size_t depth = 0;
     DumpASTNode dump(ast, &ostr, (parent ? parent->getDepth() : depth));
@@ -95,7 +96,6 @@ public:
     DebugASTLog()
         : log(nullptr)
     {
-        ss.exceptions(std::ios::failbit);
         if constexpr (_enable)
             log = &Poco::Logger::get("AST");
     }
@@ -103,14 +103,14 @@ public:
     ~DebugASTLog()
     {
         if constexpr (_enable)
-            LOG_DEBUG(log, ss.str());
+            LOG_DEBUG(log, buf.str());
     }
 
-    std::ostream * stream() { return (_enable ? &ss : nullptr); }
+    WriteBuffer * stream() { return (_enable ? &buf : nullptr); }
 
 private:
     Poco::Logger * log;
-    std::stringstream ss;
+    WriteBufferFromOwnString buf;
 };
 
 

src/Parsers/IAST.cpp

@@ -89,10 +89,9 @@ size_t IAST::checkDepthImpl(size_t max_depth, size_t level) const
 
 std::string IAST::formatForErrorMessage() const
 {
-    std::stringstream ss;
+    WriteBufferFromOwnString buf;
-    ss.exceptions(std::ios::failbit);
+    format(FormatSettings(buf, true /* one line */));
-    format(FormatSettings(ss, true /* one line */));
+    return buf.str();
-    return ss.str();
 }
 
 void IAST::cloneChildren()
@@ -112,8 +111,6 @@ String IAST::getColumnName() const
 
 void IAST::FormatSettings::writeIdentifier(const String & name) const
 {
-    WriteBufferFromOStream out(ostr, 32);
-
     switch (identifier_quoting_style)
     {
         case IdentifierQuotingStyle::None:
@@ -121,36 +118,34 @@ void IAST::FormatSettings::writeIdentifier(const String & name) const
             if (always_quote_identifiers)
                 throw Exception("Incompatible arguments: always_quote_identifiers = true && identifier_quoting_style == IdentifierQuotingStyle::None",
                     ErrorCodes::BAD_ARGUMENTS);
-            writeString(name, out);
+            writeString(name, ostr);
             break;
         }
         case IdentifierQuotingStyle::Backticks:
         {
             if (always_quote_identifiers)
-                writeBackQuotedString(name, out);
+                writeBackQuotedString(name, ostr);
             else
-                writeProbablyBackQuotedString(name, out);
+                writeProbablyBackQuotedString(name, ostr);
             break;
         }
         case IdentifierQuotingStyle::DoubleQuotes:
         {
             if (always_quote_identifiers)
-                writeDoubleQuotedString(name, out);
+                writeDoubleQuotedString(name, ostr);
             else
-                writeProbablyDoubleQuotedString(name, out);
+                writeProbablyDoubleQuotedString(name, ostr);
             break;
         }
         case IdentifierQuotingStyle::BackticksMySQL:
         {
             if (always_quote_identifiers)
-                writeBackQuotedStringMySQL(name, out);
+                writeBackQuotedStringMySQL(name, ostr);
             else
-                writeProbablyBackQuotedStringMySQL(name, out);
+                writeProbablyBackQuotedStringMySQL(name, ostr);
             break;
         }
     }
-
-    out.next();
 }
 
 }

src/Parsers/IAST.h

@@ -5,6 +5,7 @@
 #include <Parsers/IdentifierQuotingStyle.h>
 #include <Common/Exception.h>
 #include <Common/TypePromotion.h>
+#include <IO/WriteBufferFromString.h>
 
 #include <algorithm>
 #include <ostream>
@@ -161,7 +162,7 @@ public:
     /// Format settings.
     struct FormatSettings
     {
-        std::ostream & ostr;
+        WriteBuffer & ostr;
         bool hilite = false;
         bool one_line;
         bool always_quote_identifiers = false;
@@ -169,13 +170,13 @@ public:
 
         char nl_or_ws;
 
-        FormatSettings(std::ostream & ostr_, bool one_line_)
+        FormatSettings(WriteBuffer & ostr_, bool one_line_)
             : ostr(ostr_), one_line(one_line_)
         {
             nl_or_ws = one_line ? ' ' : '\n';
         }
 
-        FormatSettings(std::ostream & ostr_, const FormatSettings & other)
+        FormatSettings(WriteBuffer & ostr_, const FormatSettings & other)
             : ostr(ostr_), hilite(other.hilite), one_line(other.one_line),
             always_quote_identifiers(other.always_quote_identifiers), identifier_quoting_style(other.identifier_quoting_style)
         {
@@ -242,17 +243,17 @@ private:
 template <typename AstArray>
 std::string IAST::formatForErrorMessage(const AstArray & array)
 {
-    std::stringstream ss;
+    WriteBufferFromOwnString buf;
-    ss.exceptions(std::ios::failbit);
     for (size_t i = 0; i < array.size(); ++i)
     {
         if (i > 0)
         {
-            ss << ", ";
+            const char * delim = ", ";
+            buf.write(delim, strlen(delim));
         }
-        array[i]->format(IAST::FormatSettings(ss, true /* one line */));
+        array[i]->format(IAST::FormatSettings(buf, true /* one line */));
     }
-    return ss.str();
+    return buf.str();
 }
 
 }

src/Parsers/formatAST.cpp

@@ -5,9 +5,9 @@
 namespace DB
 {
 
-void formatAST(const IAST & ast, std::ostream & s, bool hilite, bool one_line)
+void formatAST(const IAST & ast, WriteBuffer & buf, bool hilite, bool one_line)
 {
-    IAST::FormatSettings settings(s, one_line);
+    IAST::FormatSettings settings(buf, one_line);
     settings.hilite = hilite;
 
     ast.format(settings);
@@ -15,10 +15,9 @@ void formatAST(const IAST & ast, std::ostream & s, bool hilite, bool one_line)
 
 String serializeAST(const IAST & ast, bool one_line)
 {
-    std::stringstream ss;
+    WriteBufferFromOwnString buf;
-    ss.exceptions(std::ios::failbit);
+    formatAST(ast, buf, false, one_line);
-    formatAST(ast, ss, false, one_line);
+    return buf.str();
-    return ss.str();
 }
 
 }

src/Parsers/formatAST.h

@@ -7,23 +7,25 @@
 namespace DB
 {
 
+class WriteBuffer;
+
 /** Takes a syntax tree and turns it back into text.
   * In case of INSERT query, the data will be missing.
   */
-void formatAST(const IAST & ast, std::ostream & s, bool hilite = true, bool one_line = false);
+void formatAST(const IAST & ast, WriteBuffer & buf, bool hilite = true, bool one_line = false);
 
 String serializeAST(const IAST & ast, bool one_line = true);
 
-inline std::ostream & operator<<(std::ostream & os, const IAST & ast)
+//inline std::ostream & operator<<(std::ostream & os, const IAST & ast)
-{
+//{
-    formatAST(ast, os, false, true);
+//    formatAST(ast, os, false, true);
-    return os;
+//    return os;
-}
+//}
-
+//
-inline std::ostream & operator<<(std::ostream & os, const ASTPtr & ast)
+//inline std::ostream & operator<<(std::ostream & os, const ASTPtr & ast)
-{
+//{
-    formatAST(*ast, os, false, true);
+//    formatAST(*ast, os, false, true);
-    return os;
+//    return os;
-}
+//}
 
 }

src/Parsers/formatSettingName.cpp

@@ -2,13 +2,13 @@
 #include <Common/StringUtils/StringUtils.h>
 #include <Common/quoteString.h>
 #include <common/find_symbols.h>
-#include <ostream>
+#include <IO/Operators.h>
 
 
 namespace DB
 {
 
-void formatSettingName(const String & setting_name, std::ostream & out)
+void formatSettingName(const String & setting_name, WriteBuffer & out)
 {
     if (isValidIdentifier(setting_name))
     {

src/Parsers/formatSettingName.h

@@ -7,9 +7,11 @@
 namespace DB
 {
 
+class WriteBuffer;
+
 /// Outputs built-in or custom setting's name.
 /// The function is like backQuoteIfNeed() but didn't quote with backticks
 /// if the name consists of identifiers joined with dots.
-void formatSettingName(const String & setting_name, std::ostream & out);
+void formatSettingName(const String & setting_name, WriteBuffer & out);
 
 }

src/Parsers/queryToString.cpp

@@ -1,6 +1,5 @@
 #include <Parsers/queryToString.h>
 #include <Parsers/formatAST.h>
-#include <sstream>
 
 namespace DB
 {
@@ -11,9 +10,6 @@ namespace DB
 
     String queryToString(const IAST & query)
     {
-        std::ostringstream out;
+        return serializeAST(query);
-        out.exceptions(std::ios::failbit);
-        formatAST(query, out, false, true);
-        return out.str();
     }
 }

src/Parsers/tests/create_parser.cpp

@@ -4,6 +4,7 @@
 #include <Parsers/ParserCreateQuery.h>
 #include <Parsers/formatAST.h>
 #include <Parsers/parseQuery.h>
+#include <IO/WriteBufferFromOStream.h>
 
 
 int main(int, char **)
@@ -14,7 +15,8 @@ int main(int, char **)
     ParserCreateQuery parser;
     ASTPtr ast = parseQuery(parser, input.data(), input.data() + input.size(), "", 0, 0);
 
-    formatAST(*ast, std::cerr);
+    WriteBufferFromOStream out(std::cerr, 4096);
+    formatAST(*ast, out);
     std::cerr << std::endl;
 
     return 0;

src/Parsers/tests/gtest_dictionary_parser.cpp

@@ -8,6 +8,7 @@
 #include <Parsers/DumpASTNode.h>
 #include <Parsers/TablePropertiesQueriesASTs.h>
 #include <Parsers/ParserTablePropertiesQuery.h>
+#include <IO/WriteBufferFromString.h>
 
 #include <gtest/gtest.h>
 
@@ -17,10 +18,9 @@ using namespace DB;
 
 static String astToString(IAST * ast)
 {
-    std::ostringstream oss;
+    WriteBufferFromOwnString buf;
-    oss.exceptions(std::ios::failbit);
+    dumpAST(*ast, buf);
-    dumpAST(*ast, oss);
+    return buf.str();
-    return oss.str();
 }
 
 /// Tests for external dictionaries DDL parser

src/Parsers/tests/select_parser.cpp

@@ -3,6 +3,7 @@
 #include <Parsers/ParserQueryWithOutput.h>
 #include <Parsers/parseQuery.h>
 #include <Parsers/formatAST.h>
+#include <IO/WriteBufferFromOStream.h>
 
 
 int main(int, char **)
@@ -25,7 +26,8 @@ try
     ASTPtr ast = parseQuery(parser, input.data(), input.data() + input.size(), "", 0, 0);
 
     std::cout << "Success." << std::endl;
-    formatAST(*ast, std::cerr);
+    WriteBufferFromOStream out(std::cerr, 4096);
+    formatAST(*ast, out);
     std::cout << std::endl;
 
     return 0;

src/Storages/MergeTree/ReplicatedMergeTreeQueue.cpp

@@ -1693,13 +1693,12 @@ std::vector<MergeTreeMutationStatus> ReplicatedMergeTreeQueue::getMutationsStatu
 
         for (const MutationCommand & command : entry.commands)
         {
-            std::stringstream ss;
+            WriteBufferFromOwnString buf;
-            ss.exceptions(std::ios::failbit);
+            formatAST(*command.ast, buf, false, true);
-            formatAST(*command.ast, ss, false, true);
             result.push_back(MergeTreeMutationStatus
             {
                 entry.znode_name,
-                ss.str(),
+                buf.str(),
                 entry.create_time,
                 entry.block_numbers,
                 parts_to_mutate,

src/Storages/MergeTree/ReplicatedMergeTreeTableMetadata.cpp

@@ -18,10 +18,9 @@ static String formattedAST(const ASTPtr & ast)
 {
     if (!ast)
         return "";
-    std::stringstream ss;
+    WriteBufferFromOwnString buf;
-    ss.exceptions(std::ios::failbit);
+    formatAST(*ast, buf, false, true);
-    formatAST(*ast, ss, false, true);
+    return buf.str();
-    return ss.str();
 }
 
 ReplicatedMergeTreeTableMetadata::ReplicatedMergeTreeTableMetadata(const MergeTreeData & data, const StorageMetadataPtr & metadata_snapshot)

src/Storages/MutationCommands.cpp

@@ -126,10 +126,9 @@ std::shared_ptr<ASTAlterCommandList> MutationCommands::ast() const
 
 void MutationCommands::writeText(WriteBuffer & out) const
 {
-    std::stringstream commands_ss;
+    WriteBufferFromOwnString commands_buf;
-    commands_ss.exceptions(std::ios::failbit);
+    formatAST(*ast(), commands_buf, /* hilite = */ false, /* one_line = */ true);
-    formatAST(*ast(), commands_ss, /* hilite = */ false, /* one_line = */ true);
+    out << escape << commands_buf.str();
-    out << escape << commands_ss.str();
 }
 
 void MutationCommands::readText(ReadBuffer & in)

src/Storages/StorageMergeTree.cpp

@@ -538,13 +538,12 @@ std::vector<MergeTreeMutationStatus> StorageMergeTree::getMutationsStatus() cons
 
         for (const MutationCommand & command : entry.commands)
         {
-            std::stringstream ss;
+            WriteBufferFromOwnString buf;
-            ss.exceptions(std::ios::failbit);
+            formatAST(*command.ast, buf, false, true);
-            formatAST(*command.ast, ss, false, true);
             result.push_back(MergeTreeMutationStatus
             {
                 entry.file_name,
-                ss.str(),
+                buf.str(),
                 entry.create_time,
                 block_numbers_map,
                 parts_to_do_names,

src/Storages/transformQueryForExternalDatabase.cpp

@@ -220,8 +220,7 @@ String transformQueryForExternalDatabase(
     ASTPtr select_ptr = select;
     dropAliases(select_ptr);
 
-    std::stringstream out;
+    WriteBufferFromOwnString out;
-    out.exceptions(std::ios::failbit);
     IAST::FormatSettings settings(out, true);
     settings.identifier_quoting_style = identifier_quoting_style;
     settings.always_quote_identifiers = identifier_quoting_style != IdentifierQuotingStyle::None;

utils/db-generator/query_db_generator.cpp

@@ -16,6 +16,7 @@
 #include <Parsers/ParserQueryWithOutput.h>
 #include <Parsers/formatAST.h>
 #include <Parsers/parseQuery.h>
+#include <IO/WriteBufferFromString.h>
 
 #include <boost/algorithm/string.hpp>
 #include <boost/program_options.hpp>
@@ -828,9 +829,9 @@ FuncRet arithmeticFunc(DB::ASTPtr ch, std::map<std::string, Column> & columns)
         FuncRet r(ret_type, "");
         if (no_indent)
         {
-            std::ostringstream ss;
+            DB::WriteBufferFromOwnString buf;
-            formatAST(*ch, ss);
+            formatAST(*ch, buf);
-            r.value = ss.str();
+            r.value = buf.str();
         }
         return r;
     }
@@ -990,10 +991,10 @@ FuncRet simpleFunc(DB::ASTPtr ch, std::map<std::string, Column> & columns)
         {
             if (no_indent)
             {
-                std::ostringstream ss;
+                DB::WriteBufferFromOwnString buf;
-                formatAST(*ch, ss);
+                formatAST(*ch, buf);
                 auto r = func_to_return_type[boost::algorithm::to_lower_copy(x->name)];
-                r.value = ss.str();
+                r.value = buf.str();
                 return r;
             }
             return func_to_return_type[boost::algorithm::to_lower_copy(x->name)];
@@ -1003,11 +1004,11 @@ FuncRet simpleFunc(DB::ASTPtr ch, std::map<std::string, Column> & columns)
         {
             if (no_indent)
             {
-                std::ostringstream ss;
+                DB::WriteBufferFromOwnString buf;
-                formatAST(*ch, ss);
+                formatAST(*ch, buf);
                 return FuncRet(
                         func_to_param_type[boost::algorithm::to_lower_copy(x->name)],
-                        ss.str());
+                        buf.str());
             }
             return FuncRet(
                     func_to_param_type[boost::algorithm::to_lower_copy(x->name)],