Package ganeti :: Module query :: Class _FilterCompilerHelper

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Class _FilterCompilerHelper

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Converts a query filter to a callable usable for filtering.

Instance Methods

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__init__(self, fields)
Initializes this class.

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callable

__call__(self, hints, filter_)
Converts a query filter into a callable function.

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_Compile(self, filter_, level)
Inner function for converting filters.

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_LookupField(self, name)
Returns a field definition by name.

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_HandleLogicOp(self, hints_fn, level, op, op_fn, operands)
Handles logic operators.

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_HandleUnaryOp(self, hints_fn, level, op, op_fn, operands)
Handles unary operators.

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_HandleBinaryOp(self, hints_fn, level, op, op_data, operands)
Handles binary operators.

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Class Variables

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_LEVELS_MAX = 10
How deep filters can be nested

_EQUALITY_CHECKS = [(QFF_HOSTNAME, lambda lhs, rhs: utils.Matc...
Known operators

_OPS = {qlang.OP_OR:(_OPTYPE_LOGIC, compat.any), qlang.OP_AND:...

Method Details

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init(self, fields)
(Constructor)

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Initializes this class.

Parameters:

fields - Field definitions (return value of _PrepareFieldList)

call(self, hints, filter_)
(Call operator)

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Converts a query filter into a callable function.

Parameters:

hints (_FilterHints or None) - Callbacks doing analysis on filter
filter_ (list) - Filter structure

Returns: callable

Function receiving context and item as parameters, returning boolean as to whether item matches filter

_Compile(self, filter_, level)

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Inner function for converting filters.

Calls the correct handler functions for the top-level operator. This function is called recursively (e.g. for logic operators).

_HandleLogicOp(self, hints_fn, level, op, op_fn, operands)

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Handles logic operators.

Parameters:

hints_fn (callable) - Callback doing some analysis on the filter
level (integer) - Current depth
op (string) - Operator
op_fn (callable) - Function implementing operator
operands (list) - List of operands

_HandleUnaryOp(self, hints_fn, level, op, op_fn, operands)

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Handles unary operators.

Parameters:

hints_fn (callable) - Callback doing some analysis on the filter
level (integer) - Current depth
op (string) - Operator
op_fn (callable) - Function implementing operator
operands (list) - List of operands

_HandleBinaryOp(self, hints_fn, level, op, op_data, operands)

source code

Handles binary operators.

Parameters:

hints_fn (callable) - Callback doing some analysis on the filter
level (integer) - Current depth
op (string) - Operator
op_data - Functions implementing operators
operands (list) - List of operands

Class Variable Details

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_EQUALITY_CHECKS

Known operators

Operator as key (qlang.OP_*), value a tuple of operator group (_OPTYPE_*) and a group-specific value:

_OPTYPE_LOGIC: Callable taking any number of arguments; used by _HandleLogicOp
_OPTYPE_UNARY: Always None; details handled by _HandleUnaryOp
_OPTYPE_BINARY: Callable taking exactly two parameters, the left- and right-hand side of the operator, used by _HandleBinaryOp

Value:

[(QFF_HOSTNAME, lambda lhs, rhs: utils.MatchNameComponent(rhs, [lhs], 
case_sensitive= False), None), (None, operator.eq, None),]

_OPS

Value:

{qlang.OP_OR:(_OPTYPE_LOGIC, compat.any), qlang.OP_AND:(_OPTYPE_LOGIC,
 compat.all), qlang.OP_NOT:(_OPTYPE_UNARY, None), qlang.OP_TRUE:(_OPTY
PE_UNARY, None), qlang.OP_EQUAL:(_OPTYPE_BINARY, _EQUALITY_CHECKS), ql
ang.OP_NOT_EQUAL:(_OPTYPE_BINARY, [(flags, compat.partial(_WrapNot, fn
), valprepfn) for(flags, fn, valprepfn) in _EQUALITY_CHECKS]), qlang.O
P_REGEXP:(_OPTYPE_BINARY, [(None, lambda lhs, rhs: rhs.search(lhs), _P
repareRegex),]), qlang.OP_CONTAINS:(_OPTYPE_BINARY, [(None, operator.c
ontains, None),]),}

Class _FilterCompilerHelper

__init__(self, fields) (Constructor)

__call__(self, hints, filter_) (Call operator)

_Compile(self, filter_, level)

_HandleLogicOp(self, hints_fn, level, op, op_fn, operands)

_HandleUnaryOp(self, hints_fn, level, op, op_fn, operands)

_HandleBinaryOp(self, hints_fn, level, op, op_data, operands)

_EQUALITY_CHECKS

_OPS

init(self, fields)
(Constructor)

call(self, hints, filter_)
(Call operator)