Files
scylladb/cql3/constants.hh
Jesse Haber-Kucharsky 509626fe08 Support duration CQL native type
`duration` is a new native type that was introduced in Cassandra 3.10 [1].

Support for parsing and the internal representation of the type was added in
8fa47b74e8.

Important note: The version of cqlsh distributed with Scylla does not have
support for durations included (it was added to Cassandra in [2]). To test this
change, you can use cqlsh distributed with Cassandra.

Duration types are useful when working with time-series tables, because they can
be used to manipulate date-time values in relative terms.

Two interesting applications are:

- Aggregation by time intervals [3]:

`SELECT * FROM my_table GROUP BY floor(time, 3h)`

- Querying on changes in date-times:

`SELECT ... WHERE last_heartbeat_time < now() - 3h`

(Note: neither of these is currently supported, though columns with duration
values are.)

Internally, durations are represented as three signed counters: one for months,
for days, and for nanoseconds. Each of these counters is serialized using a
variable-length encoding which is described in version 5 of the CQL native
protocol specification.

The representation of a duration as three counters means that a semantic
ordering on durations doesn't exist: Is `1mo` greater than `1mo1d`? We cannot
know, because some months have more days than others. Durations can only have a
concrete absolute value when they are "attached" to absolute date-time
references. For example, `2015-04-31 at 12:00:00 + 1mo`.

That duration values are not comparable presents some difficulties for the
implementation, because most CQL types are. Like in Cassandra's implementation
[2], I adopted a similar strategy to the way restrictions on the `counter` type
are checked. A type "references" a duration if it is either a duration or it
contains a duration (like a `tuple<..., duration, ...>`, or a UDT with a
duration member).

The following restrictions apply on durations. Note that some of these contexts
are either experimental features (materialized views), or not currently
supported at run-time (though support exists in the parser and code, so it is
prudent to add the restrictions now):

- Durations cannot appear in any part of a primary key, either for tables or
  materialized views.

- Durations cannot be directly used as the element type of a `set`, nor can they
  be used as the key type of a `map`. Because internal ordering on durations is
  based on a byte-level comparison, this property of Cassandra was intended to
  help avoid user confusion around ordering of collection elements.

- Secondary indexes on durations are not supported.

- "Slice" relations (<=, <, >=, >) are not supported on durations with `WHERE`
   restrictions (like `SELECT ... WHERE span <= 3d`). Multi-column restrictions
   only work with clustering columns, which cannot be `duration` due to the
   first rule.

- "Slice" relations are not supported on durations with query conditions (like
  `UPDATE my_table ... IF span > 5us`).

Backwards incompatibility note:

As described in the documentation [4], duration literals take one of two
forms: either ISO 8601 formats (there are three), or a "standard" format. The ISO
8601 formats start with "P" (like "P5W"). Therefore, identifiers that have this
form are no longer supported.

Fixes #2240.

[1] https://issues.apache.org/jira/browse/CASSANDRA-11873

[2] bfd57d13b7

[3] https://issues.apache.org/jira/browse/CASSANDRA-11871

[4] http://cassandra.apache.org/doc/latest/cql/types.html#working-with-durations
2017-08-10 15:01:10 -04:00

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/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*/
/*
* Copyright (C) 2015 ScyllaDB
*
* Modified by ScyllaDB
*/
/*
* This file is part of Scylla.
*
* Scylla is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Scylla is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Scylla. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include "cql3/abstract_marker.hh"
#include "cql3/update_parameters.hh"
#include "cql3/operation.hh"
#include "cql3/values.hh"
#include "cql3/term.hh"
#include "core/shared_ptr.hh"
namespace cql3 {
/**
* Static helper methods and classes for constants.
*/
class constants {
public:
#if 0
private static final Logger logger = LoggerFactory.getLogger(Constants.class);
#endif
public:
enum class type {
STRING, INTEGER, UUID, FLOAT, BOOLEAN, HEX, DURATION
};
/**
* A constant value, i.e. a ByteBuffer.
*/
class value : public terminal {
public:
cql3::raw_value _bytes;
value(cql3::raw_value bytes_) : _bytes(std::move(bytes_)) {}
virtual cql3::raw_value get(const query_options& options) override { return _bytes; }
virtual cql3::raw_value_view bind_and_get(const query_options& options) override { return _bytes.to_view(); }
virtual sstring to_string() const override { return to_hex(*_bytes); }
};
static thread_local const ::shared_ptr<value> UNSET_VALUE;
class null_literal final : public term::raw {
private:
class null_value final : public value {
public:
null_value() : value(cql3::raw_value::make_null()) {}
virtual ::shared_ptr<terminal> bind(const query_options& options) override { return {}; }
virtual sstring to_string() const override { return "null"; }
};
static thread_local const ::shared_ptr<terminal> NULL_VALUE;
public:
virtual ::shared_ptr<term> prepare(database& db, const sstring& keyspace, ::shared_ptr<column_specification> receiver) override {
if (!is_assignable(test_assignment(db, keyspace, receiver))) {
throw exceptions::invalid_request_exception("Invalid null value for counter increment/decrement");
}
return NULL_VALUE;
}
virtual assignment_testable::test_result test_assignment(database& db,
const sstring& keyspace,
::shared_ptr<column_specification> receiver) override {
return receiver->type->is_counter()
? assignment_testable::test_result::NOT_ASSIGNABLE
: assignment_testable::test_result::WEAKLY_ASSIGNABLE;
}
virtual sstring to_string() const override {
return "null";
}
};
static thread_local const ::shared_ptr<term::raw> NULL_LITERAL;
class literal : public term::raw {
private:
const type _type;
const sstring _text;
public:
literal(type type_, sstring text)
: _type{type_}
, _text{text}
{ }
static ::shared_ptr<literal> string(sstring text) {
// This is a workaround for antlr3 not distinguishing between
// calling in lexer setText() with an empty string and not calling
// setText() at all.
if (text.size() == 1 && text[0] == -1) {
text.reset();
}
return ::make_shared<literal>(type::STRING, text);
}
static ::shared_ptr<literal> integer(sstring text) {
return ::make_shared<literal>(type::INTEGER, text);
}
static ::shared_ptr<literal> floating_point(sstring text) {
return ::make_shared<literal>(type::FLOAT, text);
}
static ::shared_ptr<literal> uuid(sstring text) {
return ::make_shared<literal>(type::UUID, text);
}
static ::shared_ptr<literal> bool_(sstring text) {
return ::make_shared<literal>(type::BOOLEAN, text);
}
static ::shared_ptr<literal> hex(sstring text) {
return ::make_shared<literal>(type::HEX, text);
}
static ::shared_ptr<literal> duration(sstring text) {
return ::make_shared<literal>(type::DURATION, text);
}
virtual ::shared_ptr<term> prepare(database& db, const sstring& keyspace, ::shared_ptr<column_specification> receiver);
private:
bytes parsed_value(data_type validator);
public:
const sstring& get_raw_text() {
return _text;
}
virtual assignment_testable::test_result test_assignment(database& db, const sstring& keyspace, ::shared_ptr<column_specification> receiver);
virtual sstring to_string() const override {
return _type == type::STRING ? sstring(sprint("'%s'", _text)) : _text;
}
};
class marker : public abstract_marker {
public:
marker(int32_t bind_index, ::shared_ptr<column_specification> receiver)
: abstract_marker{bind_index, std::move(receiver)}
{
assert(!_receiver->type->is_collection());
}
virtual cql3::raw_value_view bind_and_get(const query_options& options) override {
try {
auto value = options.get_value_at(_bind_index);
if (value) {
_receiver->type->validate(*value);
}
return value;
} catch (const marshal_exception& e) {
throw exceptions::invalid_request_exception(e.what());
}
}
virtual ::shared_ptr<terminal> bind(const query_options& options) override {
auto bytes = bind_and_get(options);
if (!bytes) {
return ::shared_ptr<terminal>{};
}
return ::make_shared<constants::value>(std::move(cql3::raw_value::make_value(to_bytes(*bytes))));
}
};
class setter : public operation {
public:
using operation::operation;
virtual void execute(mutation& m, const clustering_key_prefix& prefix, const update_parameters& params) override {
auto value = _t->bind_and_get(params._options);
if (value.is_null()) {
m.set_cell(prefix, column, std::move(make_dead_cell(params)));
} else if (value.is_value()) {
m.set_cell(prefix, column, std::move(make_cell(*value, params)));
}
}
};
struct adder final : operation {
using operation::operation;
virtual void execute(mutation& m, const clustering_key_prefix& prefix, const update_parameters& params) override {
auto value = _t->bind_and_get(params._options);
if (value.is_null()) {
throw exceptions::invalid_request_exception("Invalid null value for counter increment");
} else if (value.is_unset_value()) {
return;
}
auto increment = value_cast<int64_t>(long_type->deserialize_value(*value));
m.set_cell(prefix, column, make_counter_update_cell(increment, params));
}
};
struct subtracter final : operation {
using operation::operation;
virtual void execute(mutation& m, const clustering_key_prefix& prefix, const update_parameters& params) override {
auto value = _t->bind_and_get(params._options);
if (value.is_null()) {
throw exceptions::invalid_request_exception("Invalid null value for counter increment");
} else if (value.is_unset_value()) {
return;
}
auto increment = value_cast<int64_t>(long_type->deserialize_value(*value));
if (increment == std::numeric_limits<int64_t>::min()) {
throw exceptions::invalid_request_exception(sprint("The negation of %d overflows supported counter precision (signed 8 bytes integer)", increment));
}
m.set_cell(prefix, column, make_counter_update_cell(-increment, params));
}
};
class deleter : public operation {
public:
deleter(const column_definition& column)
: operation(column, {})
{ }
virtual void execute(mutation& m, const clustering_key_prefix& prefix, const update_parameters& params) override;
};
};
std::ostream& operator<<(std::ostream&out, constants::type t);
}