Safe Haskell	None
Language	Haskell2010

Haxl.Core.Stats

Contents

Data-source stats
Profiling
Allocation

Description

Types and operations for statistics and profiling. Most users should import Haxl.Core instead of importing this module directly.

Synopsis

newtype Stats = Stats [FetchStats]
data FetchStats
- = FetchStats {
  - fetchDataSource :: Text
  - fetchBatchSize :: !Int
  - fetchStart :: !Timestamp
  - fetchDuration :: !Microseconds
  - fetchSpace :: !Int64
  - fetchFailures :: !Int
  }
- | FetchCall {
  - fetchReq :: String
  - fetchStack :: [String]
  }
type Microseconds = Int64
type Timestamp = Microseconds
getTimestamp :: IO Timestamp
emptyStats :: Stats
numFetches :: Stats -> Int
ppStats :: Stats -> String
ppFetchStats :: FetchStats -> String
data Profile
emptyProfile :: Profile
profile :: Profile -> HashMap ProfileLabel ProfileData
type ProfileLabel = Text
data ProfileData = ProfileData {
- profileAllocs :: !AllocCount
- profileDeps :: HashSet ProfileLabel
- profileFetches :: HashMap Text Int
- profileMemoHits :: !MemoHitCount
}
emptyProfileData :: ProfileData
type AllocCount = Int64
type MemoHitCount = Int64
getAllocationCounter :: IO Int64
setAllocationCounter :: Int64 -> IO ()

Data-source stats

newtype Stats Source #

Stats that we collect along the way.

Constructors

Stats [FetchStats]

Instances

Show Stats Source #
Instance details Defined in Haxl.Core.Stats Methods showsPrec :: Int -> Stats -> ShowS # show :: Stats -> String # showList :: [Stats] -> ShowS #
Semigroup Stats Source #
Instance details Defined in Haxl.Core.Stats Methods (<>) :: Stats -> Stats -> Stats # sconcat :: NonEmpty Stats -> Stats # stimes :: Integral b => b -> Stats -> Stats #
Monoid Stats Source #
Instance details Defined in Haxl.Core.Stats Methods mempty :: Stats # mappend :: Stats -> Stats -> Stats # mconcat :: [Stats] -> Stats #
ToJSON Stats Source #
Instance details Defined in Haxl.Core.Stats Methods toJSON :: Stats -> Value # toEncoding :: Stats -> Encoding # toJSONList :: [Stats] -> Value # toEncodingList :: [Stats] -> Encoding #

data FetchStats Source #

Maps data source name to the number of requests made in that round. The map only contains entries for sources that made requests in that round.

Constructors

FetchStats	Timing stats for a (batched) data fetch
Fields fetchDataSource :: Text fetchBatchSize :: !Int fetchStart :: !Timestamp fetchDuration :: !Microseconds fetchSpace :: !Int64 fetchFailures :: !Int
FetchCall	The stack trace of a call to `dataFetch`. These are collected only when profiling and reportLevel is 5 or greater.
Fields fetchReq :: String fetchStack :: [String]

Instances

Show FetchStats Source #
Instance details Defined in Haxl.Core.Stats Methods showsPrec :: Int -> FetchStats -> ShowS # show :: FetchStats -> String # showList :: [FetchStats] -> ShowS #
ToJSON FetchStats Source #
Instance details Defined in Haxl.Core.Stats Methods toJSON :: FetchStats -> Value # toEncoding :: FetchStats -> Encoding # toJSONList :: [FetchStats] -> Value # toEncodingList :: [FetchStats] -> Encoding #

type Microseconds = Int64 Source #

type Timestamp = Microseconds Source #

getTimestamp :: IO Timestamp Source #

emptyStats :: Stats Source #

numFetches :: Stats -> Int Source #

ppStats :: Stats -> String Source #

Pretty-print Stats.

ppFetchStats :: FetchStats -> String Source #

Pretty-print RoundStats.

Profiling

data Profile Source #

emptyProfile :: Profile Source #

profile :: Profile -> HashMap ProfileLabel ProfileData Source #

Data on individual labels.

type ProfileLabel = Text Source #

data ProfileData Source #

Constructors

ProfileData
Fields profileAllocs :: !AllocCount allocations made by this label profileDeps :: HashSet ProfileLabel labels that this label depends on profileFetches :: HashMap Text Int map from datasource name => fetch count profileMemoHits :: !MemoHitCount number of hits to memoized computation at this label

Instances

Show ProfileData Source #
Instance details Defined in Haxl.Core.Stats Methods showsPrec :: Int -> ProfileData -> ShowS # show :: ProfileData -> String # showList :: [ProfileData] -> ShowS #

emptyProfileData :: ProfileData Source #

type AllocCount = Int64 Source #

type MemoHitCount = Int64 Source #

Allocation

getAllocationCounter :: IO Int64 #

Return the current value of the allocation counter for the current thread.

Since: base-4.8.0.0

setAllocationCounter :: Int64 -> IO () #

Every thread has an allocation counter that tracks how much memory has been allocated by the thread. The counter is initialized to zero, and setAllocationCounter sets the current value. The allocation counter counts *down*, so in the absence of a call to setAllocationCounter its value is the negation of the number of bytes of memory allocated by the thread.

There are two things that you can do with this counter:

Use it as a simple profiling mechanism, with getAllocationCounter.
Use it as a resource limit. See enableAllocationLimit.

Allocation accounting is accurate only to about 4Kbytes.

Since: base-4.8.0.0