[chore]: Bump github.com/jackc/pgx/v5 from 5.4.3 to 5.5.0 (#2336)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
This commit is contained in:
dependabot[bot]
2023-11-06 14:44:53 +00:00
committed by GitHub
parent 74b600655d
commit 9b76afc851
47 changed files with 2905 additions and 162 deletions

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package genstack
// GenStack implements a generational stack.
//
// GenStack works as common stack except for the fact that all elements in the
// older generation are guaranteed to be popped before any element in the newer
// generation. New elements are always pushed to the current (newest)
// generation.
//
// We could also say that GenStack behaves as a stack in case of a single
// generation, but it behaves as a queue of individual generation stacks.
type GenStack[T any] struct {
// We can represent arbitrary number of generations using 2 stacks. The
// new stack stores all new pushes and the old stack serves all reads.
// Old stack can represent multiple generations. If old == new, then all
// elements pushed in previous (not current) generations have already
// been popped.
old *stack[T]
new *stack[T]
}
// NewGenStack creates a new empty GenStack.
func NewGenStack[T any]() *GenStack[T] {
s := &stack[T]{}
return &GenStack[T]{
old: s,
new: s,
}
}
func (s *GenStack[T]) Pop() (T, bool) {
// Pushes always append to the new stack, so if the old once becomes
// empty, it will remail empty forever.
if s.old.len() == 0 && s.old != s.new {
s.old = s.new
}
if s.old.len() == 0 {
var zero T
return zero, false
}
return s.old.pop(), true
}
// Push pushes a new element at the top of the stack.
func (s *GenStack[T]) Push(v T) { s.new.push(v) }
// NextGen starts a new stack generation.
func (s *GenStack[T]) NextGen() {
if s.old == s.new {
s.new = &stack[T]{}
return
}
// We need to pop from the old stack to the top of the new stack. Let's
// have an example:
//
// Old: <bottom> 4 3 2 1
// New: <bottom> 8 7 6 5
// PopOrder: 1 2 3 4 5 6 7 8
//
//
// To preserve pop order, we have to take all elements from the old
// stack and push them to the top of new stack:
//
// New: 8 7 6 5 4 3 2 1
//
s.new.push(s.old.takeAll()...)
// We have the old stack allocated and empty, so why not to reuse it as
// new new stack.
s.old, s.new = s.new, s.old
}
// Len returns number of elements in the stack.
func (s *GenStack[T]) Len() int {
l := s.old.len()
if s.old != s.new {
l += s.new.len()
}
return l
}

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package genstack
// stack is a wrapper around an array implementing a stack.
//
// We cannot use slice to represent the stack because append might change the
// pointer value of the slice. That would be an issue in GenStack
// implementation.
type stack[T any] struct {
arr []T
}
// push pushes a new element at the top of a stack.
func (s *stack[T]) push(vs ...T) { s.arr = append(s.arr, vs...) }
// pop pops the stack top-most element.
//
// If stack length is zero, this method panics.
func (s *stack[T]) pop() T {
idx := s.len() - 1
val := s.arr[idx]
// Avoid memory leak
var zero T
s.arr[idx] = zero
s.arr = s.arr[:idx]
return val
}
// takeAll returns all elements in the stack in order as they are stored - i.e.
// the top-most stack element is the last one.
func (s *stack[T]) takeAll() []T {
arr := s.arr
s.arr = nil
return arr
}
// len returns number of elements in the stack.
func (s *stack[T]) len() int { return len(s.arr) }