pub struct IntervalLogIterator<'a> { /* private fields */ }
Expand description
Parse interval logs.
This iterator exposes each item (excluding comments and other information-free lines). See
LogEntry
.
Because histogram deserialization is deferred, parsing logs is fast. See the interval_log
benchmark if you wish to see how it does on your hardware. As a baseline, parsing a log of 1000
random histograms of 10,000 values each takes 2ms total on an E5-1650v3.
Deferring deserialization is handy because it allows you to cheaply navigate the log to find the records you care about (e.g. ones in a certain time range, or with a certain tag) without doing all the allocation, etc, of deserialization.
If you’re looking for a direct port of the Java impl’s HistogramLogReader
, this isn’t one: it
won’t deserialize for you, and it pushes the burden of figuring out what to do with StartTime,
BaseTime, etc to you, and there aren’t built in functions to filter by timestamp. On the other
hand, because it doesn’t do those things, it is much more flexible: you can easily build any
sort of filtering you want, not just timestamp ranges, because you have cheap access to all the
metadata before incurring the cost of deserialization. If you’re not using any timestamp
headers, or at least using them in straightforward ways, it is easy to accumulate the
timestamp state you need. Since all the parsing is taken care of already, writing your own
HistogramLogReader
equivalent that fits the way your logs are assembled is just a couple of
lines. (And if you’re doing complex stuff, we probably wouldn’t have built something that fits
your quirky logs anyway!)
This parses from a slice representing the complete file because it made implementation easier
(and also supports mmap’d files for maximum parsing speed). If parsing from a Read
is
important for your use case, open an issue about it.
Implementations§
source§impl<'a> IntervalLogIterator<'a>
impl<'a> IntervalLogIterator<'a>
sourcepub fn new(input: &'a [u8]) -> IntervalLogIterator<'a> ⓘ
pub fn new(input: &'a [u8]) -> IntervalLogIterator<'a> ⓘ
Create a new iterator from the UTF-8 bytes of an interval log.
Trait Implementations§
source§impl<'a> Iterator for IntervalLogIterator<'a>
impl<'a> Iterator for IntervalLogIterator<'a>
§type Item = Result<LogEntry<'a>, LogIteratorError>
type Item = Result<LogEntry<'a>, LogIteratorError>
source§fn next(&mut self) -> Option<Self::Item>
fn next(&mut self) -> Option<Self::Item>
source§fn next_chunk<const N: usize>(
&mut self,
) -> Result<[Self::Item; N], IntoIter<Self::Item, N>>where
Self: Sized,
fn next_chunk<const N: usize>(
&mut self,
) -> Result<[Self::Item; N], IntoIter<Self::Item, N>>where
Self: Sized,
iter_next_chunk
)N
values. Read more1.0.0 · source§fn size_hint(&self) -> (usize, Option<usize>)
fn size_hint(&self) -> (usize, Option<usize>)
1.0.0 · source§fn count(self) -> usizewhere
Self: Sized,
fn count(self) -> usizewhere
Self: Sized,
1.0.0 · source§fn last(self) -> Option<Self::Item>where
Self: Sized,
fn last(self) -> Option<Self::Item>where
Self: Sized,
source§fn advance_by(&mut self, n: usize) -> Result<(), NonZero<usize>>
fn advance_by(&mut self, n: usize) -> Result<(), NonZero<usize>>
iter_advance_by
)n
elements. Read more1.0.0 · source§fn nth(&mut self, n: usize) -> Option<Self::Item>
fn nth(&mut self, n: usize) -> Option<Self::Item>
n
th element of the iterator. Read more1.28.0 · source§fn step_by(self, step: usize) -> StepBy<Self>where
Self: Sized,
fn step_by(self, step: usize) -> StepBy<Self>where
Self: Sized,
1.0.0 · source§fn chain<U>(self, other: U) -> Chain<Self, <U as IntoIterator>::IntoIter>
fn chain<U>(self, other: U) -> Chain<Self, <U as IntoIterator>::IntoIter>
1.0.0 · source§fn zip<U>(self, other: U) -> Zip<Self, <U as IntoIterator>::IntoIter>where
Self: Sized,
U: IntoIterator,
fn zip<U>(self, other: U) -> Zip<Self, <U as IntoIterator>::IntoIter>where
Self: Sized,
U: IntoIterator,
source§fn intersperse_with<G>(self, separator: G) -> IntersperseWith<Self, G>
fn intersperse_with<G>(self, separator: G) -> IntersperseWith<Self, G>
iter_intersperse
)separator
between adjacent items of the original iterator. Read more1.0.0 · source§fn map<B, F>(self, f: F) -> Map<Self, F>
fn map<B, F>(self, f: F) -> Map<Self, F>
1.0.0 · source§fn filter<P>(self, predicate: P) -> Filter<Self, P>
fn filter<P>(self, predicate: P) -> Filter<Self, P>
1.0.0 · source§fn filter_map<B, F>(self, f: F) -> FilterMap<Self, F>
fn filter_map<B, F>(self, f: F) -> FilterMap<Self, F>
1.0.0 · source§fn enumerate(self) -> Enumerate<Self>where
Self: Sized,
fn enumerate(self) -> Enumerate<Self>where
Self: Sized,
1.0.0 · source§fn skip_while<P>(self, predicate: P) -> SkipWhile<Self, P>
fn skip_while<P>(self, predicate: P) -> SkipWhile<Self, P>
1.0.0 · source§fn take_while<P>(self, predicate: P) -> TakeWhile<Self, P>
fn take_while<P>(self, predicate: P) -> TakeWhile<Self, P>
1.57.0 · source§fn map_while<B, P>(self, predicate: P) -> MapWhile<Self, P>
fn map_while<B, P>(self, predicate: P) -> MapWhile<Self, P>
1.0.0 · source§fn skip(self, n: usize) -> Skip<Self>where
Self: Sized,
fn skip(self, n: usize) -> Skip<Self>where
Self: Sized,
n
elements. Read more1.0.0 · source§fn take(self, n: usize) -> Take<Self>where
Self: Sized,
fn take(self, n: usize) -> Take<Self>where
Self: Sized,
n
elements, or fewer
if the underlying iterator ends sooner. Read more1.0.0 · source§fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F>
fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F>
source§fn map_windows<F, R, const N: usize>(self, f: F) -> MapWindows<Self, F, N>
fn map_windows<F, R, const N: usize>(self, f: F) -> MapWindows<Self, F, N>
iter_map_windows
)f
for each contiguous window of size N
over
self
and returns an iterator over the outputs of f
. Like slice::windows()
,
the windows during mapping overlap as well. Read more1.0.0 · source§fn inspect<F>(self, f: F) -> Inspect<Self, F>
fn inspect<F>(self, f: F) -> Inspect<Self, F>
1.0.0 · source§fn by_ref(&mut self) -> &mut Selfwhere
Self: Sized,
fn by_ref(&mut self) -> &mut Selfwhere
Self: Sized,
source§fn collect_into<E>(self, collection: &mut E) -> &mut E
fn collect_into<E>(self, collection: &mut E) -> &mut E
iter_collect_into
)1.0.0 · source§fn partition<B, F>(self, f: F) -> (B, B)
fn partition<B, F>(self, f: F) -> (B, B)
source§fn is_partitioned<P>(self, predicate: P) -> bool
fn is_partitioned<P>(self, predicate: P) -> bool
iter_is_partitioned
)true
precede all those that return false
. Read more1.27.0 · source§fn try_fold<B, F, R>(&mut self, init: B, f: F) -> R
fn try_fold<B, F, R>(&mut self, init: B, f: F) -> R
1.27.0 · source§fn try_for_each<F, R>(&mut self, f: F) -> R
fn try_for_each<F, R>(&mut self, f: F) -> R
1.0.0 · source§fn fold<B, F>(self, init: B, f: F) -> B
fn fold<B, F>(self, init: B, f: F) -> B
1.51.0 · source§fn reduce<F>(self, f: F) -> Option<Self::Item>
fn reduce<F>(self, f: F) -> Option<Self::Item>
source§fn try_reduce<R>(
&mut self,
f: impl FnMut(Self::Item, Self::Item) -> R,
) -> <<R as Try>::Residual as Residual<Option<<R as Try>::Output>>>::TryType
fn try_reduce<R>( &mut self, f: impl FnMut(Self::Item, Self::Item) -> R, ) -> <<R as Try>::Residual as Residual<Option<<R as Try>::Output>>>::TryType
iterator_try_reduce
)1.0.0 · source§fn all<F>(&mut self, f: F) -> bool
fn all<F>(&mut self, f: F) -> bool
1.0.0 · source§fn any<F>(&mut self, f: F) -> bool
fn any<F>(&mut self, f: F) -> bool
1.0.0 · source§fn find<P>(&mut self, predicate: P) -> Option<Self::Item>
fn find<P>(&mut self, predicate: P) -> Option<Self::Item>
1.30.0 · source§fn find_map<B, F>(&mut self, f: F) -> Option<B>
fn find_map<B, F>(&mut self, f: F) -> Option<B>
source§fn try_find<R>(
&mut self,
f: impl FnMut(&Self::Item) -> R,
) -> <<R as Try>::Residual as Residual<Option<Self::Item>>>::TryType
fn try_find<R>( &mut self, f: impl FnMut(&Self::Item) -> R, ) -> <<R as Try>::Residual as Residual<Option<Self::Item>>>::TryType
try_find
)1.0.0 · source§fn position<P>(&mut self, predicate: P) -> Option<usize>
fn position<P>(&mut self, predicate: P) -> Option<usize>
1.6.0 · source§fn max_by_key<B, F>(self, f: F) -> Option<Self::Item>
fn max_by_key<B, F>(self, f: F) -> Option<Self::Item>
1.15.0 · source§fn max_by<F>(self, compare: F) -> Option<Self::Item>
fn max_by<F>(self, compare: F) -> Option<Self::Item>
1.6.0 · source§fn min_by_key<B, F>(self, f: F) -> Option<Self::Item>
fn min_by_key<B, F>(self, f: F) -> Option<Self::Item>
1.15.0 · source§fn min_by<F>(self, compare: F) -> Option<Self::Item>
fn min_by<F>(self, compare: F) -> Option<Self::Item>
1.0.0 · source§fn unzip<A, B, FromA, FromB>(self) -> (FromA, FromB)
fn unzip<A, B, FromA, FromB>(self) -> (FromA, FromB)
1.36.0 · source§fn copied<'a, T>(self) -> Copied<Self>
fn copied<'a, T>(self) -> Copied<Self>
source§fn array_chunks<const N: usize>(self) -> ArrayChunks<Self, N>where
Self: Sized,
fn array_chunks<const N: usize>(self) -> ArrayChunks<Self, N>where
Self: Sized,
iter_array_chunks
)N
elements of the iterator at a time. Read more1.11.0 · source§fn product<P>(self) -> P
fn product<P>(self) -> P
source§fn cmp_by<I, F>(self, other: I, cmp: F) -> Ordering
fn cmp_by<I, F>(self, other: I, cmp: F) -> Ordering
iter_order_by
)Iterator
with those
of another with respect to the specified comparison function. Read more1.5.0 · source§fn partial_cmp<I>(self, other: I) -> Option<Ordering>
fn partial_cmp<I>(self, other: I) -> Option<Ordering>
PartialOrd
elements of
this Iterator
with those of another. The comparison works like short-circuit
evaluation, returning a result without comparing the remaining elements.
As soon as an order can be determined, the evaluation stops and a result is returned. Read moresource§fn partial_cmp_by<I, F>(self, other: I, partial_cmp: F) -> Option<Ordering>where
Self: Sized,
I: IntoIterator,
F: FnMut(Self::Item, <I as IntoIterator>::Item) -> Option<Ordering>,
fn partial_cmp_by<I, F>(self, other: I, partial_cmp: F) -> Option<Ordering>where
Self: Sized,
I: IntoIterator,
F: FnMut(Self::Item, <I as IntoIterator>::Item) -> Option<Ordering>,
iter_order_by
)Iterator
with those
of another with respect to the specified comparison function. Read moresource§fn eq_by<I, F>(self, other: I, eq: F) -> bool
fn eq_by<I, F>(self, other: I, eq: F) -> bool
iter_order_by
)1.5.0 · source§fn lt<I>(self, other: I) -> bool
fn lt<I>(self, other: I) -> bool
Iterator
are lexicographically
less than those of another. Read more1.5.0 · source§fn le<I>(self, other: I) -> bool
fn le<I>(self, other: I) -> bool
Iterator
are lexicographically
less or equal to those of another. Read more1.5.0 · source§fn gt<I>(self, other: I) -> bool
fn gt<I>(self, other: I) -> bool
Iterator
are lexicographically
greater than those of another. Read more1.5.0 · source§fn ge<I>(self, other: I) -> bool
fn ge<I>(self, other: I) -> bool
Iterator
are lexicographically
greater than or equal to those of another. Read more