Struct mongodb::cursor::Cursor
[−]
[src]
pub struct Cursor { /* fields omitted */ }
Maintains a connection to the server and lazily returns documents from a query.
Fields
client
- The client to read from.
namespace
- The namespace to read and write from.
batch_size
- How many documents to fetch at a given time from the server.
cursor_id
- Uniquely identifies the cursor being returned by the reply.
limit
- An upper bound on the total number of documents this cursor
should return.
count
- How many documents have been returned so far.
buffer
- A cache for documents received from the query that have not
yet been returned.
Methods
impl Cursor
[src]
fn command_cursor(client: Client,
db: &str,
doc: Document,
cmd_type: CommandType,
read_pref: ReadPreference)
-> Result<Cursor>
db: &str,
doc: Document,
cmd_type: CommandType,
read_pref: ReadPreference)
-> Result<Cursor>
Construcs a new Cursor for a database command.
Arguments
client
- Client making the request.
db
- Which database the command is being sent to.
doc
- Specifies the command that is being run.
Return value
Returns the newly created Cursor on success, or an Error on failure.
fn query(client: Client,
namespace: String,
batch_size: i32,
flags: OpQueryFlags,
number_to_skip: i32,
number_to_return: i32,
query: Document,
return_field_selector: Option<Document>,
cmd_type: CommandType,
is_cmd_cursor: bool,
read_pref: ReadPreference)
-> Result<Cursor>
namespace: String,
batch_size: i32,
flags: OpQueryFlags,
number_to_skip: i32,
number_to_return: i32,
query: Document,
return_field_selector: Option<Document>,
cmd_type: CommandType,
is_cmd_cursor: bool,
read_pref: ReadPreference)
-> Result<Cursor>
Executes a query where the batch size of the returned cursor is specified.
Arguments
client
- The client to read from.
namespace
- The namespace to read and write from.
batch_size
- How many documents the cursor should return at a time.
flags
- Bit vector of query options.
number_to_skip
- The number of initial documents to skip over in the
query results.
number_to_return - The total number of documents that should be returned by the query.
return_field_selector - An optional projection of which fields should
be present in the documents to be returned by
the query.
is_cmd_cursor
- Whether or not the Cursor is for a database command.
monitor_host
- The host being monitored, if this is a query from a server monitor.
Return value
Returns the cursor for the query results on success, or an Error on failure.
fn query_with_stream(stream: PooledStream,
client: Client,
namespace: String,
batch_size: i32,
flags: OpQueryFlags,
number_to_skip: i32,
number_to_return: i32,
query: Document,
return_field_selector: Option<Document>,
cmd_type: CommandType,
is_cmd_cursor: bool,
read_pref: Option<ReadPreference>)
-> Result<Cursor>
client: Client,
namespace: String,
batch_size: i32,
flags: OpQueryFlags,
number_to_skip: i32,
number_to_return: i32,
query: Document,
return_field_selector: Option<Document>,
cmd_type: CommandType,
is_cmd_cursor: bool,
read_pref: Option<ReadPreference>)
-> Result<Cursor>
fn next_n(&mut self, n: i32) -> Result<Vec<Document>>
Attempts to read a specified number of BSON documents from the cursor.
Arguments
n
- The number of documents to read.
Return value
Returns a vector containing the BSON documents that were read.
fn next_batch(&mut self) -> Result<Vec<Document>>
Attempts to read a batch of BSON documents from the cursor.
Return value
Returns a vector containing the BSON documents that were read.
fn has_next(&mut self) -> Result<bool>
Checks whether there are any more documents for the cursor to return.
Return value
Returns true
if the cursor is not yet exhausted, or false
if it is.
Trait Implementations
impl Iterator for Cursor
[src]
type Item = Result<Document>
The type of the elements being iterated over.
fn next(&mut self) -> Option<Result<Document>>
Attempts to read a BSON document from the cursor.
Return value
Returns a BSON document if there is another one to return; None
if
there are no more documents to return; or an Error if the request for
another document fails.
fn size_hint(&self) -> (usize, Option<usize>)
1.0.0
Returns the bounds on the remaining length of the iterator. Read more
fn count(self) -> usize
1.0.0
Consumes the iterator, counting the number of iterations and returning it. Read more
fn last(self) -> Option<Self::Item>
1.0.0
Consumes the iterator, returning the last element. Read more
fn nth(&mut self, n: usize) -> Option<Self::Item>
1.0.0
Returns the n
th element of the iterator. Read more
fn chain<U>(self, other: U) -> Chain<Self, U::IntoIter> where U: IntoIterator<Item=Self::Item>
1.0.0
Takes two iterators and creates a new iterator over both in sequence. Read more
fn zip<U>(self, other: U) -> Zip<Self, U::IntoIter> where U: IntoIterator
1.0.0
'Zips up' two iterators into a single iterator of pairs. Read more
fn map<B, F>(self, f: F) -> Map<Self, F> where F: FnMut(Self::Item) -> B
1.0.0
Takes a closure and creates an iterator which calls that closure on each element. Read more
fn filter<P>(self, predicate: P) -> Filter<Self, P> where P: FnMut(&Self::Item) -> bool
1.0.0
Creates an iterator which uses a closure to determine if an element should be yielded. Read more
fn filter_map<B, F>(self, f: F) -> FilterMap<Self, F> where F: FnMut(Self::Item) -> Option<B>
1.0.0
Creates an iterator that both filters and maps. Read more
fn enumerate(self) -> Enumerate<Self>
1.0.0
Creates an iterator which gives the current iteration count as well as the next value. Read more
fn peekable(self) -> Peekable<Self>
1.0.0
Creates an iterator which can use peek
to look at the next element of the iterator without consuming it. Read more
fn skip_while<P>(self, predicate: P) -> SkipWhile<Self, P> where P: FnMut(&Self::Item) -> bool
1.0.0
Creates an iterator that [skip()
]s elements based on a predicate. Read more
fn take_while<P>(self, predicate: P) -> TakeWhile<Self, P> where P: FnMut(&Self::Item) -> bool
1.0.0
Creates an iterator that yields elements based on a predicate. Read more
fn skip(self, n: usize) -> Skip<Self>
1.0.0
Creates an iterator that skips the first n
elements. Read more
fn take(self, n: usize) -> Take<Self>
1.0.0
Creates an iterator that yields its first n
elements. Read more
fn scan<St, B, F>(self, initial_state: St, f: F) -> Scan<Self, St, F> where F: FnMut(&mut St, Self::Item) -> Option<B>
1.0.0
An iterator adaptor similar to [fold()
] that holds internal state and produces a new iterator. Read more
fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F> where F: FnMut(Self::Item) -> U, U: IntoIterator
1.0.0
Creates an iterator that works like map, but flattens nested structure. Read more
fn fuse(self) -> Fuse<Self>
1.0.0
Creates an iterator which ends after the first None
. Read more
fn inspect<F>(self, f: F) -> Inspect<Self, F> where F: FnMut(&Self::Item) -> ()
1.0.0
Do something with each element of an iterator, passing the value on. Read more
fn by_ref(&mut self) -> &mut Self
1.0.0
Borrows an iterator, rather than consuming it. Read more
fn collect<B>(self) -> B where B: FromIterator<Self::Item>
1.0.0
Transforms an iterator into a collection. Read more
fn partition<B, F>(self, f: F) -> (B, B) where B: Default + Extend<Self::Item>, F: FnMut(&Self::Item) -> bool
1.0.0
Consumes an iterator, creating two collections from it. Read more
fn fold<B, F>(self, init: B, f: F) -> B where F: FnMut(B, Self::Item) -> B
1.0.0
An iterator adaptor that applies a function, producing a single, final value. Read more
fn all<F>(&mut self, f: F) -> bool where F: FnMut(Self::Item) -> bool
1.0.0
Tests if every element of the iterator matches a predicate. Read more
fn any<F>(&mut self, f: F) -> bool where F: FnMut(Self::Item) -> bool
1.0.0
Tests if any element of the iterator matches a predicate. Read more
fn find<P>(&mut self, predicate: P) -> Option<Self::Item> where P: FnMut(&Self::Item) -> bool
1.0.0
Searches for an element of an iterator that satisfies a predicate. Read more
fn position<P>(&mut self, predicate: P) -> Option<usize> where P: FnMut(Self::Item) -> bool
1.0.0
Searches for an element in an iterator, returning its index. Read more
fn rposition<P>(&mut self, predicate: P) -> Option<usize> where P: FnMut(Self::Item) -> bool, Self: ExactSizeIterator + DoubleEndedIterator
1.0.0
Searches for an element in an iterator from the right, returning its index. Read more
fn max(self) -> Option<Self::Item> where Self::Item: Ord
1.0.0
Returns the maximum element of an iterator. Read more
fn min(self) -> Option<Self::Item> where Self::Item: Ord
1.0.0
Returns the minimum element of an iterator. Read more
fn max_by_key<B, F>(self, f: F) -> Option<Self::Item> where B: Ord, F: FnMut(&Self::Item) -> B
1.6.0
Returns the element that gives the maximum value from the specified function. Read more
fn max_by<F>(self, compare: F) -> Option<Self::Item> where F: FnMut(&Self::Item, &Self::Item) -> Ordering
iter_max_by
)Returns the element that gives the maximum value with respect to the specified comparison function. Read more
fn min_by_key<B, F>(self, f: F) -> Option<Self::Item> where B: Ord, F: FnMut(&Self::Item) -> B
1.6.0
Returns the element that gives the minimum value from the specified function. Read more
fn min_by<F>(self, compare: F) -> Option<Self::Item> where F: FnMut(&Self::Item, &Self::Item) -> Ordering
iter_min_by
)Returns the element that gives the minimum value with respect to the specified comparison function. Read more
fn rev(self) -> Rev<Self> where Self: DoubleEndedIterator
1.0.0
Reverses an iterator's direction. Read more
fn unzip<A, B, FromA, FromB>(self) -> (FromA, FromB) where FromA: Default + Extend<A>, FromB: Default + Extend<B>, Self: Iterator<Item=(A, B)>
1.0.0
Converts an iterator of pairs into a pair of containers. Read more
fn cloned<'a, T>(self) -> Cloned<Self> where Self: Iterator<Item=&'a T>, T: 'a + Clone
1.0.0
Creates an iterator which clone()
s all of its elements. Read more
fn cycle(self) -> Cycle<Self> where Self: Clone
1.0.0
Repeats an iterator endlessly. Read more
fn sum<S>(self) -> S where S: Sum<Self::Item>
1.11.0
Sums the elements of an iterator. Read more
fn product<P>(self) -> P where P: Product<Self::Item>
1.11.0
Iterates over the entire iterator, multiplying all the elements Read more
fn cmp<I>(self, other: I) -> Ordering where I: IntoIterator<Item=Self::Item>, Self::Item: Ord
1.5.0
Lexicographically compares the elements of this Iterator
with those of another. Read more
fn partial_cmp<I>(self, other: I) -> Option<Ordering> where I: IntoIterator, Self::Item: PartialOrd<I::Item>
1.5.0
Lexicographically compares the elements of this Iterator
with those of another. Read more
fn eq<I>(self, other: I) -> bool where I: IntoIterator, Self::Item: PartialEq<I::Item>
1.5.0
Determines if the elements of this Iterator
are equal to those of another. Read more
fn ne<I>(self, other: I) -> bool where I: IntoIterator, Self::Item: PartialEq<I::Item>
1.5.0
Determines if the elements of this Iterator
are unequal to those of another. Read more
fn lt<I>(self, other: I) -> bool where I: IntoIterator, Self::Item: PartialOrd<I::Item>
1.5.0
Determines if the elements of this Iterator
are lexicographically less than those of another. Read more
fn le<I>(self, other: I) -> bool where I: IntoIterator, Self::Item: PartialOrd<I::Item>
1.5.0
Determines if the elements of this Iterator
are lexicographically less or equal to those of another. Read more
fn gt<I>(self, other: I) -> bool where I: IntoIterator, Self::Item: PartialOrd<I::Item>
1.5.0
Determines if the elements of this Iterator
are lexicographically greater than those of another. Read more
fn ge<I>(self, other: I) -> bool where I: IntoIterator, Self::Item: PartialOrd<I::Item>
1.5.0
Determines if the elements of this Iterator
are lexicographically greater than or equal to those of another. Read more