Class: Google::Cloud::Bigtable::RowFilter::ChainFilter

Inherits:
Object
  • Object
show all
Defined in:
lib/google/cloud/bigtable/row_filter/chain_filter.rb

Overview

ChainFilter

A RowFilter that sends rows through several RowFilters in sequence.

The elements of "filters" are chained together to process the input row:

in row -> f(0) -> intermediate row -> f(1) -> ... -> f(N) -> out row

The full chain is executed atomically.

Examples:

require "google/cloud/bigtable"

chain = Google::Cloud::Bigtable::RowFilter.chain
# Add filters to chain filter
chain.key("user-*").label "users"

Instance Method Summary collapse

Instance Method Details

#block ⇒ Google::Cloud::Bigtable::RowFilter::ChainFilter

Adds a block-all filter.

Does not match any cells, regardless of input. Useful for temporarily disabling just part of a filter.

Examples:

require "google/cloud/bigtable"

filter = Google::Cloud::Bigtable::RowFilter.chain.block

Returns:



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# File 'lib/google/cloud/bigtable/row_filter/chain_filter.rb', line 202

def block
  add RowFilter.block
end

#cells_per_column(limit) ⇒ Google::Cloud::Bigtable::RowFilter::ChainFilter

Adds a cells-per-column filter.

Matches only the most recent N cells within each column. For example, if N=2, this filter would match column foo:bar at timestamps 10 and 9, skip all earlier cells in foo:bar, and then begin matching again in column foo:bar2. If duplicate cells are present, as is possible when using an Interleave, each copy of the cell is counted separately.

Examples:

require "google/cloud/bigtable"

filter = Google::Cloud::Bigtable::RowFilter.chain.cells_per_column 5

Parameters:

  • limit (String) —

    Max cell match per column limit.

Returns:



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# File 'lib/google/cloud/bigtable/row_filter/chain_filter.rb', line 452

def cells_per_column limit
  add RowFilter.cells_per_column(limit)
end

#cells_per_row(limit) ⇒ Google::Cloud::Bigtable::RowFilter::ChainFilter

Adds a cells-per-row-limit filter.

Matches only the first N cells of each row. If duplicate cells are present, as is possible when using an Interleave, each copy of the cell is counted separately.

Examples:

require "google/cloud/bigtable"

filter = Google::Cloud::Bigtable::RowFilter.chain.cells_per_row 5

Parameters:

  • limit (String) —

    Max cell match per row limit.

Returns:



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# File 'lib/google/cloud/bigtable/row_filter/chain_filter.rb', line 429

def cells_per_row limit
  add RowFilter.cells_per_row(limit)
end

#cells_per_row_offset(offset) ⇒ Google::Cloud::Bigtable::RowFilter::ChainFilter

Adds a cell-per-row-offset filter instance to skip the first N cells.

Skips the first N cells of each row, matching all subsequent cells. If duplicate cells are present, as is possible when using an Interleave, each copy of the cell is counted separately.

Examples:

require "google/cloud/bigtable"

filter = Google::Cloud::Bigtable::RowFilter.chain.cells_per_row_offset 3

Parameters:

  • offset (Integer) —

    Offset value.

Returns:



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# File 'lib/google/cloud/bigtable/row_filter/chain_filter.rb', line 409

def cells_per_row_offset offset
  add RowFilter.cells_per_row_offset(offset)
end

#chain(filter) ⇒ Google::Cloud::Bigtable::RowFilter::ChainFilter

Adds a chain filter.

A Chain RowFilter that sends rows through several RowFilters in sequence.

The elements of "filters" are chained together to process the input row:

in row -> f(0) -> intermediate row -> f(1) -> ... -> f(N) -> out row

The full chain is executed atomically.

Examples:

Create a chain filter and add a chain filter.

require "google/cloud/bigtable"

chain_1 = Google::Cloud::Bigtable::RowFilter.chain

# Add filters to chain filter
chain_1.key("user-*").cells_per_row 5

filter = Google::Cloud::Bigtable::RowFilter.chain
filter.chain chain_1

# OR
filter = Google::Cloud::Bigtable::RowFilter.chain.chain chain_1

Parameters:

Returns:

Raises:



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# File 'lib/google/cloud/bigtable/row_filter/chain_filter.rb', line 76

def chain filter
  raise RowFilterError, "Filter type must be ChainFilter" unless filter.instance_of? ChainFilter
  add filter
end

#column_range(range) ⇒ Google::Cloud::Bigtable::RowFilter::ChainFilter

Adds a column-range filter.

Matches only cells from columns within the given range.

Examples:

require "google/cloud/bigtable"

range = Google::Cloud::Bigtable::ColumnRange.new("cf").from("field0").to("field5")

filter = Google::Cloud::Bigtable::RowFilter.chain.column_range range

Parameters:

Returns:



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# File 'lib/google/cloud/bigtable/row_filter/chain_filter.rb', line 536

def column_range range
  add RowFilter.column_range(range)
end

#condition(filter) ⇒ Google::Cloud::Bigtable::RowFilter::ChainFilter

Adds a condition filter.

A RowFilter that evaluates one of two possible RowFilters, depending on whether or not a predicate RowFilter outputs any cells from the input row.

IMPORTANT NOTE: The predicate filter does not execute atomically with the true and false filters, which may lead to inconsistent or unexpected results. Additionally, condition filters have poor performance, especially when filters are set for the false condition.

Cannot be used within the predicate_filter, true_filter, or false_filter.

Examples:

require "google/cloud/bigtable"

predicate = Google::Cloud::Bigtable::RowFilter.key "user-*"

label = Google::Cloud::Bigtable::RowFilter.label "user"
strip_value = Google::Cloud::Bigtable::RowFilter.strip_value

condition_filter = Google::Cloud::Bigtable::RowFilter.condition(predicate)
                                                     .on_match(label)
                                                     .otherwise(strip_value)

filter = Google::Cloud::Bigtable::RowFilter.chain.condition condition_filter

Parameters:

Returns:

Raises:



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# File 'lib/google/cloud/bigtable/row_filter/chain_filter.rb', line 165

def condition filter
  raise RowFilterError, "Filter type must be ConditionFilter" unless filter.instance_of? ConditionFilter
  add filter
end

#family(regex) ⇒ Google::Cloud::Bigtable::RowFilter::ChainFilter

Adds a family-name-match filter using a regular expression.

Matches only cells from columns whose families satisfy the given RE2 regex. For technical reasons, the regex must not contain the : character, even if it is not being used as a literal. Note that, since column families cannot contain the new line character \n, it is sufficient to use . as a full wildcard when matching column family names.

For Regex syntax:

Examples:

require "google/cloud/bigtable"

filter = Google::Cloud::Bigtable::RowFilter.chain.family "cf-*"

Parameters:

  • regex (String) —

    Regex to match family name.

Returns:

See Also:



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# File 'lib/google/cloud/bigtable/row_filter/chain_filter.rb', line 309

def family regex
  add RowFilter.family(regex)
end

#filters ⇒ Array<SimpleFilter|ChainFilter|InterleaveFilter|ConditionFilter>

Returns a frozen copy of the filters array.

Returns:



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# File 'lib/google/cloud/bigtable/row_filter/chain_filter.rb', line 560

def filters
  @filters.dup.freeze
end

#interleave(filter) ⇒ Google::Cloud::Bigtable::RowFilter::ChainFilter

Adds an interleave filter.

A RowFilter that sends each row to each of several component RowFilters and interleaves the results.

The elements of "filters" all process a copy of the input row, and the results are pooled, sorted, and combined into a single output row. If multiple cells are produced with the same column and timestamp, they will all appear in the output row in an unspecified mutual order. Consider the following example, with three filters:

                             input row
                                 |
       -----------------------------------------------------
       |                         |                         |
      f(0)                      f(1)                      f(2)
       |                         |                         |
1: foo,bar,10,x             foo,bar,10,z              far,bar,7,a
2: foo,blah,11,z            far,blah,5,x              far,blah,5,x
       |                         |                         |
       -----------------------------------------------------
                                 |
1:                      foo,bar,10,z   # could have switched with #2
2:                      foo,bar,10,x   # could have switched with #1
3:                      foo,blah,11,z
4:                      far,bar,7,a
5:                      far,blah,5,x   # identical to #6
6:                      far,blah,5,x   # identical to #5

All interleaved filters are executed atomically.

See InterleaveFilter

Examples:

Add an interleave filter to the chain filter.

require "google/cloud/bigtable"

interleave = Google::Cloud::Bigtable::RowFilter.interleave

# Add filters to interleave filter
interleave.key("user-*").cells_per_column(3)

chain = Google::Cloud::Bigtable::RowFilter.chain.interleave interleave

Parameters:

Returns:

Raises:



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# File 'lib/google/cloud/bigtable/row_filter/chain_filter.rb', line 129

def interleave filter
  raise RowFilterError, "Filter type must be InterleaveFilter" unless filter.instance_of? InterleaveFilter
  add filter
end

#key(regex) ⇒ Google::Cloud::Bigtable::RowFilter::ChainFilter

Adds a key-filter instance to match keys using a regular expression.

Matches only cells from rows whose keys satisfy the given RE2 regex. In other words, passes through the entire row when the key matches, and otherwise produces an empty row. Note that, since row keys can contain arbitrary bytes, the \C escape sequence must be used if a true wildcard is desired. The . character will not match the new line character \n, which may be present in a binary key.

For Regex syntax:

Examples:

require "google/cloud/bigtable"

filter = Google::Cloud::Bigtable::RowFilter.chain.key "user-*"

Parameters:

  • regex (String) —

    Regex to match row keys.

Returns:

See Also:



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# File 'lib/google/cloud/bigtable/row_filter/chain_filter.rb', line 263

def key regex
  add RowFilter.key(regex)
end

#label(value) ⇒ Google::Cloud::Bigtable::RowFilter::ChainFilter

Adds a label filter instance to apply a label based on the result of read rows.

Applies the given label to all cells in the output row. This allows the client to determine which results were produced from which part of the filter.

Values must be at most 15 characters and match the RE2 pattern [a-z0-9\\-]+

Due to a technical limitation, it is not possible to apply multiple labels to a cell. As a result, a chain may have no more than one sub-filter that contains an apply_label_transformer. It is okay for an Interleave to contain multiple apply_label_transformers, as they will be applied to separate copies of the input.

Examples:

require "google/cloud/bigtable"

filter = Google::Cloud::Bigtable::RowFilter.chain.label "user-detail"

Parameters:

  • value (String) —

    Label name

Returns:



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# File 'lib/google/cloud/bigtable/row_filter/chain_filter.rb', line 389

def label value
  add RowFilter.label(value)
end

#length ⇒ Integer

Gets the number of filters in the chain.

Examples:

require "google/cloud/bigtable"

filter = Google::Cloud::Bigtable::RowFilter.chain.key("user-1*").label("user")
filter.length # 2

Returns:

  • (Integer) 


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# File 'lib/google/cloud/bigtable/row_filter/chain_filter.rb', line 551

def length
  @filters.length
end

#pass ⇒ Google::Cloud::Bigtable::RowFilter::ChainFilter

Adds a pass filter.

Matches all cells, regardless of input. Functionally equivalent to leaving filter unset, but included for completeness.

Examples:

require "google/cloud/bigtable"

filter = Google::Cloud::Bigtable::RowFilter.chain.pass

Returns:



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# File 'lib/google/cloud/bigtable/row_filter/chain_filter.rb', line 184

def pass
  add RowFilter.pass
end

#qualifier(regex) ⇒ Google::Cloud::Bigtable::RowFilter::ChainFilter

Adds a column-qualifier-match filter using a regular expression.

Matches only cells from columns whose qualifiers satisfy the given RE2 regex. Note that, since column qualifiers can contain arbitrary bytes, the \C escape sequence must be used if a true wildcard is desired. The . character will not match the new line character \n, which may be present in a binary qualifier.

For Regex syntax:

Examples:

require "google/cloud/bigtable"

filter = Google::Cloud::Bigtable::RowFilter.chain.qualifier "user-name*"

Parameters:

  • regex (String) —

    Regex to match column qualifier name.

Returns:

See Also:



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# File 'lib/google/cloud/bigtable/row_filter/chain_filter.rb', line 335

def qualifier regex
  add RowFilter.qualifier(regex)
end

#sample(probability) ⇒ Google::Cloud::Bigtable::RowFilter::ChainFilter

Adds a sample-probability filter.

Matches all cells from a row with probability p, and matches no cells from the row with probability 1-p.

Examples:

require "google/cloud/bigtable"

filter = Google::Cloud::Bigtable::RowFilter.chain.sample 0.5

Parameters:

  • probability (Float) —

    Probability value. Probability must be greater than 0 and less than 1.0.

Returns:



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# File 'lib/google/cloud/bigtable/row_filter/chain_filter.rb', line 283

def sample probability
  add RowFilter.sample(probability)
end

#sink ⇒ Google::Cloud::Bigtable::RowFilter::ChainFilter

Adds a sink filter.

Outputs all cells directly to the output of the read rather than to any parent filter.

Examples:

require "google/cloud/bigtable"

filter = Google::Cloud::Bigtable::RowFilter.chain.sink

Returns:



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# File 'lib/google/cloud/bigtable/row_filter/chain_filter.rb', line 219

def sink
  add RowFilter.sink
end

#strip_value ⇒ Google::Cloud::Bigtable::RowFilter::ChainFilter

Adds a strip-value filter.

Replaces each cell's value with an empty string.

Examples:

require "google/cloud/bigtable"

filter = Google::Cloud::Bigtable::RowFilter.chain.strip_value

Returns:



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# File 'lib/google/cloud/bigtable/row_filter/chain_filter.rb', line 236

def strip_value
  add RowFilter.strip_value
end

#timestamp_range(from: nil, to: nil) ⇒ Google::Cloud::Bigtable::RowFilter::ChainFilter

Adds a timestamp-range filter.

Matches only cells with timestamps within the given range. Specifies a contiguous range of timestamps.

Examples:

require "google/cloud/bigtable"

timestamp_micros = (Time.now.to_f * 1_000_000).round(-3)
from = timestamp_micros - 300_000_000
to = timestamp_micros

filter = Google::Cloud::Bigtable::RowFilter.chain.timestamp_range from: from, to: to

Parameters:

  • from (Integer) (defaults to: nil) —

    Inclusive lower bound. If left empty, interpreted as 0.

  • to (Integer) (defaults to: nil) —

    Exclusive upper bound. If left empty, interpreted as infinity.

Returns:



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# File 'lib/google/cloud/bigtable/row_filter/chain_filter.rb', line 478

def timestamp_range from: nil, to: nil
  add RowFilter.timestamp_range(from: from, to: to)
end

#value(regex) ⇒ Google::Cloud::Bigtable::RowFilter::ChainFilter

Adds a value-match filter using a regular expression.

Matches only cells with values that satisfy the given regular expression. Note that, since cell values can contain arbitrary bytes, the \C escape sequence must be used if a true wildcard is desired. The . character will not match the new line character \n, which may be present in a binary value.

For Regex syntax:

Examples:

require "google/cloud/bigtable"

filter = Google::Cloud::Bigtable::RowFilter.chain.value "abc*"

Parameters:

  • regex (String) —

    Regex to match cell value.

Returns:

See Also:



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# File 'lib/google/cloud/bigtable/row_filter/chain_filter.rb', line 360

def value regex
  add RowFilter.value(regex)
end

#value_range(range) ⇒ Google::Cloud::Bigtable::RowFilter::ChainFilter

Adds a value-range filter.

Matches only cells with values that fall within the given range.

See ValueRange#from and { Google::Cloud::Bigtable::ValueRange#to} for range option inclusive/exclusive options.

  • The value at which to start the range. If neither field is set, interpreted as an empty string, inclusive.
  • The value at which to end the range. If neither field is set, interpreted as the infinite string, exclusive.

Examples:

Start to end range.

require "google/cloud/bigtable"

bigtable = Google::Cloud::Bigtable.new
table = bigtable.table "my-instance", "my-table"

range = table.new_value_range.from("value-001").to("value-005")
filter = Google::Cloud::Bigtable::RowFilter.chain.value_range range

Start exclusive to infinite end range.

require "google/cloud/bigtable"

bigtable = Google::Cloud::Bigtable.new
table = bigtable.table "my-instance", "my-table"

range = table.new_value_range.from "value-001", inclusive: false
filter = Google::Cloud::Bigtable::RowFilter.chain.value_range range

Parameters:

Returns:



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# File 'lib/google/cloud/bigtable/row_filter/chain_filter.rb', line 516

def value_range range
  add RowFilter.value_range(range)
end