Package ganeti :: Module qlang

Module qlang

Module for a simple query language

A query filter is always a list. The first item in the list is the operator (e.g. [OP_AND, ...]), while the other items depend on the operator. For logic operators (e.g. OP_AND, OP_OR), they are subfilters whose results are combined. Unary operators take exactly one other item (e.g. a subfilter for OP_NOT and a field name for OP_TRUE). Binary operators take exactly two operands, usually a field name and a value to compare against. Filters are converted to callable functions by query._CompileFilter.

Functions

[hide private]

MakeSimpleFilter(namefield, values)
Builds simple a filter.

source code

_ConvertLogicOp(op)
Creates parsing action function for logic operator.

source code

_ConvertRegexpValue(_, loc, toks)
Regular expression value for condition.

source code

pyparsing.ParserElement

BuildFilterParser()
Builds a parser for query filter strings.

source code

list

ParseFilter(text, parser=None)
Parses a query filter.

source code

bool

_CheckFilter(text)
CHecks if a string could be a filter.

source code

bool

_CheckGlobbing(text)
Checks if a string could be a globbing pattern.

source code

_MakeFilterPart(namefield, text, isnumeric=False)
Generates filter for one argument.

source code

list

MakeFilter(args, force_filter, namefield=None, isnumeric=False)
Try to make a filter from arguments to a command.

source code

Variables

[hide private]

OP_OR = "|"

OP_AND = "&"

OP_NOT = "!"

OP_TRUE = "?"

OP_EQUAL = "="

OP_NOT_EQUAL = "!="

OP_LT = "<"

OP_LE = "<="

OP_GT = ">"

OP_GE = ">="

OP_REGEXP = "=~"

OP_CONTAINS = "=[]"

FILTER_DETECTION_CHARS = frozenset("()=/!~'\"\\<>"+ string.whi...
Characters used for detecting user-written filters (see _CheckFilter)

GLOB_DETECTION_CHARS = frozenset("*?")
Characters used to detect globbing filters (see _CheckGlobbing)

_KNOWN_REGEXP_DELIM = "/#^|"

_KNOWN_REGEXP_FLAGS = frozenset("si")

Imports: re, string, logging, pyp, errors, utils, compat

Function Details

[hide private]

MakeSimpleFilter(namefield, values)

source code

Builds simple a filter.

Parameters:

namefield - Name of field containing item name
values - List of names

_ConvertLogicOp(op)

source code

Creates parsing action function for logic operator.

Parameters:

op (string) - Operator for data structure, e.g. OP_AND

ParseFilter(text, parser=None)

source code

Parses a query filter.

Parameters:

text (string) - Query filter
parser (pyparsing.ParserElement) - Pyparsing object

Returns: list

MakeFilter(args, force_filter, namefield=None, isnumeric=False)

source code

Try to make a filter from arguments to a command.

If the name could be a filter it is parsed as such. If it's just a globbing pattern, e.g. "*.site", such a filter is constructed. As a last resort the names are treated just as a plain name filter.

Parameters:

args (list of string) - Arguments to command
force_filter (bool) - Whether to force treatment as a full-fledged filter
namefield (string) - Name of field to use for simple filters (use None for a default of "name")
isnumeric (bool) - Whether the namefield type is numeric, as opposed to the default string type; this influences how the filter is built

Returns: list

Query filter

Variables Details

[hide private]

FILTER_DETECTION_CHARS

Characters used for detecting user-written filters (see _CheckFilter)

Value:

frozenset("()=/!~'\"\\<>"+ string.whitespace)