Methods
all(pass)
Sets passAllFilter or blockAllFilter
Parameters:
| Name | Type | Description |
|---|---|---|
pass |
boolean |
Whether to passAllFilter or blockAllFilter Assign true for enabling passAllFilter and false for enabling blockAllFilter |
Example
```
//-
// Matches all cells, regardless of input. Functionally equivalent to
// leaving `filter` unset, but included for completeness.
//-
const filter = {
all: true
};
//-
// Does not match any cells, regardless of input. Useful for temporarily
// disabling just part of a filter.
//-
const filter = {
all: false
};
```column(column)
Matches only cells from columns whose qualifiers satisfy the given RE2 regex.
Parameters:
| Name | Type | Description |
|---|---|---|
column |
regex | string | object |
Matching Column to filter with 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. |
Example
```
//-
// Using the following filter, we would retrieve the `tjefferson` and
// `gwashington` columns.
//-
const filter = [
{
column: /[a-z]+on$/
}
];
//-
// You can also provide a string (optionally containing regexp characters)
// for simple column filters.
//-
const filter = [
{
column: 'gwashington'
}
];
//-
// Or you can provide an array of strings if you wish to match against
// multiple columns.
//-
const filter = [
{
column: [
'gwashington',
'tjefferson'
]
}
];
//-
// If you wish to use additional column filters, consider using the following
// syntax.
//-
const filter = [
{
column: {
name: 'gwashington'
}
}
];
//-
// <h4>Column Cell Limits</h4>
//
// Matches only the most recent number of versions within each column. For
// example, if the `versions` is set to 2, this filter would only match
// columns updated at the two most recent timestamps.
//
// If duplicate cells are present, as is possible when using an
// Filter#interleave filter, each copy of the cell is
// counted separately.
//-
const filter = [
{
column: {
cellLimit: 2
}
}
];
//-
// <h4>Column Ranges</h4>
//
// Specifies a contiguous range of columns within a single column family.
// The range spans from <column_family>:<start_qualifier> to
// <column_family>:<end_qualifier>, where both bounds can be either
// inclusive or exclusive. By default both are inclusive.
//
// When the `start` bound is omitted it is interpreted as an empty string.
// When the `end` bound is omitted it is interpreted as Infinity.
//-
const filter = [
{
column: {
family: 'follows',
start: 'gwashington',
end: 'tjefferson'
}
}
];
//-
// By default, both the `start` and `end` bounds are inclusive. You can
// override these by providing an object explicity stating whether or not it
// is `inclusive`.
//-
const filter = [
{
column: {
family: 'follows',
start: {
value: 'gwashington',
inclusive: false
},
end: {
value: 'jadams',
inclusive: false
}
}
}
];
```condition(condition)
A filter which evaluates one of two possible filters, depending on
whether or not a test filter outputs any cells from the input row.
IMPORTANT NOTE: The test filter does not execute atomically with the
pass and fail filters, which may lead to inconsistent or unexpected
results. Additionally, condition filters have poor performance, especially
when filters are set for the fail condition.
Parameters:
| Name | Type | Description |
|---|---|---|
condition |
object |
Condition to filter. |
Example
```
//-
// In the following example we're creating a filter that will check if
// `gwashington` follows `tjefferson`. If he does, we'll get all of the
// `gwashington` data. If he does not, we'll instead return all of the
// `tjefferson` data.
//-
const filter = [
{
condition: {
// If `test` outputs any cells, then `pass` will be evaluated on the
// input row. Otherwise `fail` will be evaluated.
test: [
{
row: 'gwashington'
},
{
family: 'follows'
},
{
column: 'tjefferson'
}
],
// If omitted, no results will be returned in the true case.
pass: [
{
row: 'gwashington'
}
],
// If omitted, no results will be returned in the false case.
fail: [
{
row: 'tjefferson'
}
]
}
}
];
```family(family)
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.
Parameters:
| Name | Type | Description |
|---|---|---|
family |
regex |
Expression to filter family |
interleave(filters)
Applies several filters to the data in parallel and combines the results.
Parameters:
| Name | Type | Description |
|---|---|---|
filters |
object |
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. All interleaved filters are executed atomically. |
Example
```
//-
// In the following example, we're creating a filter that will retrieve
// results for entries that were either created between December 17th, 2015
// and March 22nd, 2016 or entries that have data for `follows:tjefferson`.
//-
const filter = [
{
interleave: [
[
{
time: {
start: new Date('December 17, 2015'),
end: new Date('March 22, 2016')
}
}
],
[
{
family: 'follows'
},
{
column: 'tjefferson'
}
]
]
}
];
```label(label)
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.
Parameters:
| Name | Type | Description |
|---|---|---|
label |
string |
Label to determine filter point Values must be at most 15 characters in length, and match the RE2 pattern [a-z0-9\-]+ Due to a technical limitation, it is not currently possible to apply multiple labels to a cell. As a result, a chain filter may have no more than one sub-filter which contains a apply label transformer. It is okay for an Filter#interleave to contain multiple apply label transformers, as they will be applied to separate copies of the input. This may be relaxed in the future. |
row(row)
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.
Parameters:
| Name | Type | Description |
|---|---|---|
row |
regex | string | Array.<string> |
Row format to Filter 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. |
Example
```
//-
// In the following example we'll use a regular expression to match all
// row keys ending with the letters "on", which would then yield
// `gwashington` and `tjefferson`.
//-
const filter = [
{
row: /[a-z]+on$/
}
];
//-
// You can also provide a string (optionally containing regexp characters)
// for simple key filters.
//-
const filter = [
{
row: 'gwashington'
}
];
//-
// Or you can provide an array of strings if you wish to match against
// multiple keys.
//-
const filter = [
{
row: [
'gwashington',
'tjefferson'
]
}
];
//-
// If you wish to use additional row filters, consider using the following
// syntax.
//-
const filter = [
{
row: {
key: 'gwashington'
}
}
];
//-
// <h4>Row Samples</h4>
//
// Matches all cells from a row with probability p, and matches no cells
// from the row with probability 1-p.
//-
const filter = [
{
row: {
sample: 1
}
}
];
//-
// <h4>Row Cell Offsets</h4>
//
// Skips the first N cells of each row, matching all subsequent cells.
// If duplicate cells are present, as is possible when using an
// Filter#interleave, each copy of the cell is counted
// separately.
//-
const filter = [
{
row: {
cellOffset: 2
}
}
];
//-
// <h4>Row Cell Limits</h4>
//
// Matches only the first N cells of each row.
// If duplicate cells are present, as is possible when using an
// Filter#interleave, each copy of the cell is counted
// separately.
//-
const filter = [
{
row: {
cellLimit: 4
}
}
];
```set(key, value)
Stores a filter object.
Parameters:
| Name | Type | Description |
|---|---|---|
key |
string |
Filter name. |
value |
* |
Filter value. |
sink(sink)
This filter is meant for advanced use only. Hook for introspection into the filter. Outputs all cells directly to the output of the read rather than to any parent filter. Despite being excluded by the qualifier filter, a copy of every cell that reaches the sink is present in the final result. As with an Filter#interleave filter, duplicate cells are possible, and appear in an unspecified mutual order.
Cannot be used within Filter#condition filter.
Parameters:
| Name | Type | Description |
|---|---|---|
sink |
boolean |
Example
```
//-
// Using the following filter, a copy of every cell that reaches the sink is
// present in the final result, despite being excluded by the qualifier
// filter
//-
const filter = [
{
family: 'follows'
},
{
interleave: [
[
{
all: true
}
],
[
{
label: 'prezzy'
},
{
sink: true
}
]
]
},
{
column: 'gwashington'
}
];
//-
// As with an Filter#interleave filter, duplicate cells
// are possible, and appear in an unspecified mutual order. In this case we
// have a duplicates with multiple `gwashington` columns because one copy
// passed through the Filter#all filter while the other was
// passed through the Filter#label and sink. Note that one
// copy has label "prezzy" while the other does not.
//-
```time(time)
Matches only cells with timestamps within the given range.
Parameters:
| Name | Type | Description |
|---|---|---|
time |
object |
Start and End time Object |
Example
```
const filter = [
{
time: {
start: new Date('December 17, 2006 03:24:00'),
end: new Date()
}
}
];
```toProto()
If we detect multiple filters, we'll assume it's a chain filter and the execution of the filters will be the order in which they were specified.
value(value)
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.
Parameters:
| Name | Type | Description |
|---|---|---|
value |
string | Array.<string> | object |
Value to filter cells |
Example
```
const filter = [
{
value: /[0-9]/
}
];
//-
// You can also provide a string (optionally containing regexp characters)
// for value filters.
//-
const filter = [
{
value: '1'
}
];
//-
// You can also provide an array of strings if you wish to match against
// multiple values.
//-
const filter = [
{
value: ['1', '9']
}
];
//-
// Or you can provide a Buffer or an array of Buffers if you wish to match
// against specfic binary value(s).
//-
const userInputedFaces = [Buffer.from('.|.'), Buffer.from(':-)')];
const filter = [
{
value: userInputedFaces
}
];
//-
// <h4>Value Ranges</h4>
//
// Specifies a contiguous range of values.
//
// When the `start` bound is omitted it is interpreted as an empty string.
// When the `end` bound is omitted it is interpreted as Infinity.
//-
const filter = [
{
value: {
start: '1',
end: '9'
}
}
];
//-
// By default, both the `start` and `end` bounds are inclusive. You can
// override these by providing an object explicity stating whether or not it
// is `inclusive`.
//-
const filter = [
{
value: {
start: {
value: '1',
inclusive: false
},
end: {
value: '9',
inclusive: false
}
}
}
];
//-
// <h4>Strip Values</h4>
//
// Replaces each cell's value with an emtpy string.
//-
const filter = [
{
value: {
strip: true
}
}
];
```(static) convertToRegExpString(regex) → {string}
Parameters:
| Name | Type | Description |
|---|---|---|
regex |
regex | string | Array.<string> |
Either a plain regex, a regex in string form or an array of strings. |
Returns:
| Type | Description |
|---|---|
| string |
Throws:
TypeError
Transforms Arrays into a simple regular expression for matching multiple values.
(static) createRange(start, end, key) → {object}
Creates a range object. All bounds default to inclusive.
Parameters:
| Name | Type | Description |
|---|---|---|
start |
object | string |
Lower bound value. |
end |
object | string |
Upper bound value. |
key |
string |
Key used to create range value keys. |
Returns:
| Type | Description |
|---|---|
| object |
Example
```
const {Bigtable} = require('@google-cloud/bigtable');
const Filter = Bigtable.Filter;
const range = Filter.createRange('value1', 'value2', 'Test');
// {
// startTestInclusive: new Buffer('value1'),
// endTestExclusive: new Buffer('value2')
// }
//-
// It's also possible to pass in objects to specify inclusive/exclusive
// bounds.
//-
const upperBound = {
value: 'value3',
inclusive: false
};
const range = Filter.createRange(upperBound, null, 'Test2');
// => {
// startTest2Exclusive: 'value3'
// }
```(static) parse(filters) → {object}
Parameters:
| Name | Type | Description |
|---|---|---|
filters |
Array.<object> |
The list of filters to be parsed. |
Returns:
| Type | Description |
|---|---|
| object |
Throws:
FilterError
Turns filters into proto friendly format.