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Remove JSONEachRowRowInputStream.

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This commit is contained in:
Nikolai Kochetov 2019-08-02 18:36:36 +03:00
parent cd299bb162
commit ae50ab6907
4 changed files with 1 additions and 343 deletions
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2
dbms/src/Formats/FormatFactory.cpp
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@ -207,7 +207,6 @@ void registerInputFormatCSV(FormatFactory & factory);
void registerOutputFormatCSV(FormatFactory & factory);
void registerInputFormatTSKV(FormatFactory & factory);
void registerOutputFormatTSKV(FormatFactory & factory);
void registerInputFormatJSONEachRow(FormatFactory & factory);
void registerOutputFormatJSONEachRow(FormatFactory & factory);
void registerInputFormatParquet(FormatFactory & factory);
void registerOutputFormatParquet(FormatFactory & factory);
@ -273,7 +272,6 @@ FormatFactory::FormatFactory()
registerOutputFormatCSV(*this);
registerInputFormatTSKV(*this);
registerOutputFormatTSKV(*this);
registerInputFormatJSONEachRow(*this);
registerOutputFormatJSONEachRow(*this);
registerInputFormatProtobuf(*this);
registerOutputFormatProtobuf(*this);

272
dbms/src/Formats/JSONEachRowRowInputStream.cpp
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@ -1,272 +0,0 @@
#include <IO/ReadHelpers.h>
#include <Formats/JSONEachRowRowInputStream.h>
#include <Formats/FormatFactory.h>
#include <Formats/BlockInputStreamFromRowInputStream.h>
#include <DataTypes/NestedUtils.h>
namespace DB
{
namespace ErrorCodes
{
extern const int INCORRECT_DATA;
extern const int CANNOT_READ_ALL_DATA;
extern const int LOGICAL_ERROR;
}
namespace
{
enum
{
UNKNOWN_FIELD = size_t(-1),
NESTED_FIELD = size_t(-2)
};
}
JSONEachRowRowInputStream::JSONEachRowRowInputStream(ReadBuffer & istr_, const Block & header_, const FormatSettings & format_settings)
: istr(istr_), header(header_), format_settings(format_settings), name_map(header.columns())
{
/// In this format, BOM at beginning of stream cannot be confused with value, so it is safe to skip it.
skipBOMIfExists(istr);
size_t num_columns = header.columns();
for (size_t i = 0; i < num_columns; ++i)
{
const String & colname = columnName(i);
name_map[colname] = i; /// NOTE You could place names more cache-locally.
if (format_settings.import_nested_json)
{
const auto splitted = Nested::splitName(colname);
if (!splitted.second.empty())
{
const StringRef table_name(colname.data(), splitted.first.size());
name_map[table_name] = NESTED_FIELD;
}
}
}
prev_positions.assign(num_columns, name_map.end());
}
const String & JSONEachRowRowInputStream::columnName(size_t i) const
{
return header.getByPosition(i).name;
}
inline size_t JSONEachRowRowInputStream::columnIndex(const StringRef & name, size_t key_index)
{
/// Optimization by caching the order of fields (which is almost always the same)
/// and a quick check to match the next expected field, instead of searching the hash table.
if (prev_positions.size() > key_index
&& prev_positions[key_index] != name_map.end()
&& name == prev_positions[key_index]->getFirst())
{
return prev_positions[key_index]->getSecond();
}
else
{
const auto it = name_map.find(name);
if (name_map.end() != it)
{
if (key_index < prev_positions.size())
prev_positions[key_index] = it;
return it->getSecond();
}
else
return UNKNOWN_FIELD;
}
}
/** Read the field name and convert it to column name
* (taking into account the current nested name prefix)
* Resulting StringRef is valid only before next read from buf.
*/
StringRef JSONEachRowRowInputStream::readColumnName(ReadBuffer & buf)
{
// This is just an optimization: try to avoid copying the name into current_column_name
if (nested_prefix_length == 0 && buf.position() + 1 < buf.buffer().end())
{
char * next_pos = find_first_symbols<'\\', '"'>(buf.position() + 1, buf.buffer().end());
if (next_pos != buf.buffer().end() && *next_pos != '\\')
{
/// The most likely option is that there is no escape sequence in the key name, and the entire name is placed in the buffer.
assertChar('"', buf);
StringRef res(buf.position(), next_pos - buf.position());
buf.position() = next_pos + 1;
return res;
}
}
current_column_name.resize(nested_prefix_length);
readJSONStringInto(current_column_name, buf);
return current_column_name;
}
static inline void skipColonDelimeter(ReadBuffer & istr)
{
skipWhitespaceIfAny(istr);
assertChar(':', istr);
skipWhitespaceIfAny(istr);
}
void JSONEachRowRowInputStream::skipUnknownField(const StringRef & name_ref)
{
if (!format_settings.skip_unknown_fields)
throw Exception("Unknown field found while parsing JSONEachRow format: " + name_ref.toString(), ErrorCodes::INCORRECT_DATA);
skipJSONField(istr, name_ref);
}
void JSONEachRowRowInputStream::readField(size_t index, MutableColumns & columns)
{
if (read_columns[index])
throw Exception("Duplicate field found while parsing JSONEachRow format: " + columnName(index), ErrorCodes::INCORRECT_DATA);
try
{
header.getByPosition(index).type->deserializeAsTextJSON(*columns[index], istr, format_settings);
}
catch (Exception & e)
{
e.addMessage("(while read the value of key " + columnName(index) + ")");
throw;
}
read_columns[index] = true;
}
inline bool JSONEachRowRowInputStream::advanceToNextKey(size_t key_index)
{
skipWhitespaceIfAny(istr);
if (istr.eof())
throw Exception("Unexpected end of stream while parsing JSONEachRow format", ErrorCodes::CANNOT_READ_ALL_DATA);
else if (*istr.position() == '}')
{
++istr.position();
return false;
}
if (key_index > 0)
{
assertChar(',', istr);
skipWhitespaceIfAny(istr);
}
return true;
}
void JSONEachRowRowInputStream::readJSONObject(MutableColumns & columns)
{
assertChar('{', istr);
for (size_t key_index = 0; advanceToNextKey(key_index); ++key_index)
{
StringRef name_ref = readColumnName(istr);
const size_t column_index = columnIndex(name_ref, key_index);
if (unlikely(ssize_t(column_index) < 0))
{
/// name_ref may point directly to the input buffer
/// and input buffer may be filled with new data on next read
/// If we want to use name_ref after another reads from buffer, we must copy it to temporary string.
current_column_name.assign(name_ref.data, name_ref.size);
name_ref = StringRef(current_column_name);
skipColonDelimeter(istr);
if (column_index == UNKNOWN_FIELD)
skipUnknownField(name_ref);
else if (column_index == NESTED_FIELD)
readNestedData(name_ref.toString(), columns);
else
throw Exception("Logical error: illegal value of column_index", ErrorCodes::LOGICAL_ERROR);
}
else
{
skipColonDelimeter(istr);
readField(column_index, columns);
}
}
}
void JSONEachRowRowInputStream::readNestedData(const String & name, MutableColumns & columns)
{
current_column_name = name;
current_column_name.push_back('.');
nested_prefix_length = current_column_name.size();
readJSONObject(columns);
nested_prefix_length = 0;
}
bool JSONEachRowRowInputStream::read(MutableColumns & columns, RowReadExtension & ext)
{
skipWhitespaceIfAny(istr);
/// We consume ;, or \n before scanning a new row, instead scanning to next row at the end.
/// The reason is that if we want an exact number of rows read with LIMIT x
/// from a streaming table engine with text data format, like File or Kafka
/// then seeking to next ;, or \n would trigger reading of an extra row at the end.
/// Semicolon is added for convenience as it could be used at end of INSERT query.
if (!istr.eof() && (*istr.position() == ',' || *istr.position() == ';'))
++istr.position();
skipWhitespaceIfAny(istr);
if (istr.eof())
return false;
size_t num_columns = columns.size();
/// Set of columns for which the values were read. The rest will be filled with default values.
read_columns.assign(num_columns, false);
nested_prefix_length = 0;
readJSONObject(columns);
/// Fill non-visited columns with the default values.
for (size_t i = 0; i < num_columns; ++i)
if (!read_columns[i])
header.getByPosition(i).type->insertDefaultInto(*columns[i]);
/// return info about defaults set
ext.read_columns = read_columns;
return true;
}
void JSONEachRowRowInputStream::syncAfterError()
{
skipToUnescapedNextLineOrEOF(istr);
}
void registerInputFormatJSONEachRow(FormatFactory & factory)
{
factory.registerInputFormat("JSONEachRow", [](
ReadBuffer & buf,
const Block & sample,
const Context &,
UInt64 max_block_size,
UInt64 rows_portion_size,
FormatFactory::ReadCallback callback,
const FormatSettings & settings)
{
return std::make_shared<BlockInputStreamFromRowInputStream>(
std::make_shared<JSONEachRowRowInputStream>(buf, sample, settings),
sample, max_block_size, rows_portion_size, callback, settings);
});
}
}

68
dbms/src/Formats/JSONEachRowRowInputStream.h
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@ -1,68 +0,0 @@
#pragma once
#include <Core/Block.h>
#include <Formats/IRowInputStream.h>
#include <Formats/FormatSettings.h>
#include <Common/HashTable/HashMap.h>
namespace DB
{
class ReadBuffer;
/** A stream for reading data in JSON format, where each row is represented by a separate JSON object.
* Objects can be separated by line feed, other whitespace characters in any number and possibly a comma.
* Fields can be listed in any order (including, in different lines there may be different order),
* and some fields may be missing.
*/
class JSONEachRowRowInputStream : public IRowInputStream
{
public:
JSONEachRowRowInputStream(ReadBuffer & istr_, const Block & header_, const FormatSettings & format_settings);
bool read(MutableColumns & columns, RowReadExtension & ext) override;
bool allowSyncAfterError() const override { return true; }
void syncAfterError() override;
private:
const String & columnName(size_t i) const;
size_t columnIndex(const StringRef & name, size_t key_index);
bool advanceToNextKey(size_t key_index);
void skipUnknownField(const StringRef & name_ref);
StringRef readColumnName(ReadBuffer & buf);
void readField(size_t index, MutableColumns & columns);
void readJSONObject(MutableColumns & columns);
void readNestedData(const String & name, MutableColumns & columns);
private:
ReadBuffer & istr;
Block header;
const FormatSettings format_settings;
/// Buffer for the read from the stream field name. Used when you have to copy it.
/// Also, if processing of Nested data is in progress, it holds the common prefix
/// of the nested column names (so that appending the field name to it produces
/// the full column name)
String current_column_name;
/// If processing Nested data, holds the length of the common prefix
/// of the names of related nested columns. For example, for a table
/// created as follows
/// CREATE TABLE t (n Nested (i Int32, s String))
/// the nested column names are 'n.i' and 'n.s' and the nested prefix is 'n.'
size_t nested_prefix_length = 0;
std::vector<UInt8> read_columns;
/// Hash table match `field name -> position in the block`. NOTE You can use perfect hash map.
using NameMap = HashMap<StringRef, size_t, StringRefHash>;
NameMap name_map;
/// Cached search results for previous row (keyed as index in JSON object) - used as a hint.
std::vector<NameMap::iterator> prev_positions;
};
}

2
dbms/src/Processors/Formats/Impl/JSONEachRowRowInputFormat.h
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@ -13,7 +13,7 @@ class ReadBuffer;
/** A stream for reading data in JSON format, where each row is represented by a separate JSON object.
* Objects can be separated by feed return, other whitespace characters in any number and possibly a comma.
* Objects can be separated by line feed, other whitespace characters in any number and possibly a comma.
* Fields can be listed in any order (including, in different lines there may be different order),
* and some fields may be missing.
*/