Constructor
new TimestampedCounter(metrics, key, options)
Parameters:
| Name | Type | Description |
|---|---|---|
metrics |
RedisMetrics | An instance of a RedisMetrics client. |
key |
string | The base key to use for this counter. |
options |
Object | The options to use for this counter. The available
options are specified in |
- Source:
Methods
count(timeGranularityopt, eventObjopt, callbackopt) → {Promise}
Returns the current count for this counter.
If a specific time granularity is given, the value returned is the current value at the given granularity level. Effectively, this provides a single answer to questions such as "what is the count for the current day".
Notice: Counts cannot be returned for a given time granularity if it was not incremented at this granularity level in the first place.
Parameters:
| Name | Type | Attributes | Default | Description |
|---|---|---|---|---|
timeGranularity |
module:constants~timeGranularities |
<optional> |
'total' | The granularity level to report the count for. |
eventObj |
string | object |
<optional> |
The event object. See
|
|
callback |
function |
<optional> |
Optional callback. |
- Since:
- 0.1.0
- Source:
Returns:
A promise that resolves to the result from Redis. Can be used instead of the callback function.
- Type
- Promise
Examples
myCounter.count((err, result) => {
console.log(result); // Outputs the global count
});myCounter.count('year', (err, result) => {
console.log(result); // Outputs the count for the current year
});myCounter.count('year', '/foo.html', (err, result) => {
// Outputs the count for the current year for the event object '/foo.html'
console.log(result);
});countRange(timeGranularity, startDate, endDateopt, eventObjopt, callbackopt) → {Promise}
Returns an object mapping timestamps to counts in the given time range at a specific time granularity level.
Notice: This function does not make sense for the "none" time granularity.
Parameters:
| Name | Type | Attributes | Default | Description |
|---|---|---|---|---|
timeGranularity |
module:constants~timeGranularities | The granularity level to report the count for. |
||
startDate |
Date | Object | string | number | Start date for the range (inclusive). Accepts the same argument as the constructor of a moment date. |
||
endDate |
Date | Object | string | number |
<optional> |
new Date() | End date for the range (inclusive). Accepts the same arguments as the constructor of a moment date. |
eventObj |
string | object |
<optional> |
The event object. See
|
|
callback |
function |
<optional> |
Optional callback. |
- Since:
- 0.1.0
- Source:
Returns:
A promise that resolves to the result from Redis. Can be used instead of the callback function.
- Type
- Promise
getKeys(timeopt, timeGranularityopt) → {Array}
Return a list of Redis keys that are associated with this counter at the current point in time (default) and will be written to Redis.
Parameters:
| Name | Type | Attributes | Default | Description |
|---|---|---|---|---|
time |
Moment |
<optional> |
now | A specific time to get keys for. |
timeGranularity |
module:constants~timeGranularities |
<optional> |
The granularity level to return keys for. The default is the granularity from the options. |
- Source:
Returns:
- Type
- Array
getKeyTTL(key) → {number}
Finds the configured time to live for the given key.
Parameters:
| Name | Type | Description |
|---|---|---|
key |
string | The full key (including timestamp) for the key to determine the ttl for. |
- Source:
Returns:
Number of seconds that the key should live.
- Type
- number
incr(eventObjopt, callbackopt) → {Promise}
Increments this counter with 1.
For some use cases, it makes sense to pass in an event object to get more precise statistics for a specific event. For example, when counting page views on a page, it makes sense to increment a counter per specific page. For this use case, the eventObj parameter is a good fit.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
eventObj |
Object | string |
<optional> |
Extra event information used to determine what counter to increment. |
callback |
function |
<optional> |
Optional callback. |
- Since:
- 0.1.0
- Source:
Returns:
A promise that resolves to the results from Redis. Can be used instead of the callback function.
- Type
- Promise
incrby(amount, eventObjopt, callbackopt) → {Promise}
Increments this counter with the given amount.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
amount |
number | The amount to increment with. |
|
eventObj |
Object | string |
<optional> |
Extra event information used to
determine what counter to increment. See |
callback |
function |
<optional> |
Optional callback. |
- Since:
- 0.2.0
- Source:
- See:
Returns:
A promise that resolves to the results from Redis. Can be used instead of the callback function.
- Type
- Promise
top(timeGranularityopt, directionopt, startingAtopt, limitopt, callbackopt) → {Promise}
Returns the current top elements for this counter.
If a specific time granularity is given, the value returned is the current value at the given granularity level. Effectively, this provides a single answer to questions such as "what is the rank for the current day".
Parameters:
| Name | Type | Attributes | Default | Description |
|---|---|---|---|---|
timeGranularity |
module:constants~timeGranularities |
<optional> |
'total' | The granularity level to report the rank for. |
direction |
string |
<optional> |
desc | Optional sort direction, can be "asc" or "desc" |
startingAt |
integer |
<optional> |
0 | Optional starting row. |
limit |
integer |
<optional> |
-1 | Optional number of results to return. |
callback |
function |
<optional> |
Optional callback. |
- Since:
- 0.1.1
- Source:
Returns:
A promise that resolves to the result from Redis. Can be used instead of the callback function.
- Type
- Promise
Examples
myCounter.top((err, result) => {
console.log(result); // Outputs the global rank
});myCounter.top('year', (err, result) => {
console.log(result); // Outputs the rank for the current year
});trimEvents(keepDirectionopt, limitopt, callbackopt) → {Promise}
Permanently remove event objects for this counter so only the top-N elements remain in either descending (the default) or ascending order.
The event objects are removed with Redis' removal by rank for sorted sets (ZREMRANGEBYRANK).
The removal happens at each granularity level and only supports daily granularity and above (month, year, total) to optimize for the number of Redis keys to consider. It removes data going 5 years back in time.
If the function is used too often, there is a risk that the top-N elements will stay the same forever, because lower-ranking elements get removed before their scores have a change to increase.
Therefore, the function should only be used to try and reclaim space for big counters with a lot of event objects, and only rarely used.
Parameters:
| Name | Type | Attributes | Default | Description |
|---|---|---|---|---|
keepDirection |
string |
<optional> |
desc | Sort direction for the top-N elements to keep, can be "asc" or "desc". |
limit |
integer |
<optional> |
1000 | Number of results to keep. |
callback |
function |
<optional> |
Callback |
- Since:
- 1.1.0
- Source:
Returns:
Resolves when the values have been removed.
- Type
- Promise
Examples
// Keeps the top-5 elements with highest score
myCounter.trimEvents('desc', 5)// Keeps the top-5 elements with lowest score
myCounter.trimEvents('asc', 5)