Enum libpijul::Value [−] [src]

pub enum Value<'a, T> where
    T: 'a,  {
    Direct {
        p: *const u8,
        len: u64,
        txn: PhantomData<&'a T>,
    },
    Large {
        txn: &'a T,
        offset: u64,
        len: u64,
    },
}

Iterator over parts of a value. On values of size at most 4096 bytes, the iterator will run exactly once. On larger values, it returns all parts of the value, in order.

Variants

On-page value.

Fields of Direct

Pointer to the value.

Length.

Lifetime marker.

Indirect value, just an offset to a page and a length are stored on the page, as two u64.

Fields of Large

Transaction from which this page can be retrieved.

Offset of the page from the beginning of the file.

Total length of this value.

Methods

impl<'a, T> Value<'a, T> where
    T: LoadPage, 
[src]

Length of this value.

Clone the pointers to this value. This is actually unsafe, as it duplicates a pointer, and several copies might be stored in the database without incrementing their RC.

As long as it is never put back into a database, it should be safe.

Turns an UnsafeValue into a Value. The database from which that UnsafeValue comes must not have changed since the UnsafeValue was retrieved.

Turns a value into an unsafe value, ready to be inserted into a database.

Produces a direct value from a slice. Might exceed the maximal page size.

Turn this value into a slice, if it is inlined on a page. Panics else.

Turns this value into a std::borrow::Cow, allocating a Vec<u8> if it is too large.

Trait Implementations

impl<'a, T> Iterator for Value<'a, T> where
    T: LoadPage, 
[src]

The type of the elements being iterated over.

Advances the iterator and returns the next value. Read more

Returns the bounds on the remaining length of the iterator. Read more

Consumes the iterator, counting the number of iterations and returning it. Read more

Consumes the iterator, returning the last element. Read more

Returns the nth element of the iterator. Read more

🔬 This is a nightly-only experimental API. (iterator_step_by)

unstable replacement of Range::step_by

Creates an iterator starting at the same point, but stepping by the given amount at each iteration. Read more

Takes two iterators and creates a new iterator over both in sequence. Read more

'Zips up' two iterators into a single iterator of pairs. Read more

Takes a closure and creates an iterator which calls that closure on each element. Read more

Creates an iterator which uses a closure to determine if an element should be yielded. Read more

Creates an iterator that both filters and maps. Read more

Creates an iterator which gives the current iteration count as well as the next value. Read more

Creates an iterator which can use peek to look at the next element of the iterator without consuming it. Read more

Creates an iterator that [skip]s elements based on a predicate. Read more

Creates an iterator that yields elements based on a predicate. Read more

Creates an iterator that skips the first n elements. Read more

Creates an iterator that yields its first n elements. Read more

An iterator adaptor similar to [fold] that holds internal state and produces a new iterator. Read more

Creates an iterator that works like map, but flattens nested structure. Read more

Creates an iterator which ends after the first [None]. Read more

Do something with each element of an iterator, passing the value on. Read more

Borrows an iterator, rather than consuming it. Read more

Transforms an iterator into a collection. Read more

Consumes an iterator, creating two collections from it. Read more

An iterator adaptor that applies a function, producing a single, final value. Read more

Tests if every element of the iterator matches a predicate. Read more

Tests if any element of the iterator matches a predicate. Read more

Searches for an element of an iterator that satisfies a predicate. Read more

Searches for an element in an iterator, returning its index. Read more

Searches for an element in an iterator from the right, returning its index. Read more

Returns the maximum element of an iterator. Read more

Returns the minimum element of an iterator. Read more

Returns the element that gives the maximum value from the specified function. Read more

Returns the element that gives the maximum value with respect to the specified comparison function. Read more

Returns the element that gives the minimum value from the specified function. Read more

Returns the element that gives the minimum value with respect to the specified comparison function. Read more

Reverses an iterator's direction. Read more

Converts an iterator of pairs into a pair of containers. Read more

Creates an iterator which [clone]s all of its elements. Read more

Repeats an iterator endlessly. Read more

Sums the elements of an iterator. Read more

Iterates over the entire iterator, multiplying all the elements Read more

Lexicographically compares the elements of this Iterator with those of another. Read more

Lexicographically compares the elements of this Iterator with those of another. Read more

Determines if the elements of this Iterator are equal to those of another. Read more

Determines if the elements of this Iterator are unequal to those of another. Read more

Determines if the elements of this Iterator are lexicographically less than those of another. Read more

Determines if the elements of this Iterator are lexicographically less or equal to those of another. Read more

Determines if the elements of this Iterator are lexicographically greater than those of another. Read more

Determines if the elements of this Iterator are lexicographically greater than or equal to those of another. Read more

impl<'a, T> Debug for Value<'a, T> where
    T: LoadPage, 
[src]

Formats the value using the given formatter.