/
request_buffer.go
112 lines (92 loc) · 2.55 KB
/
request_buffer.go
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package snmpclient
/* Circular buffer object */
type requestBuffer struct {
start int /* index of oldest element */
count int /* the count of elements */
elements []*clientRequest /* vector of elements */
}
func newRequestBuffer(elements []*clientRequest) *requestBuffer {
return &requestBuffer{elements: elements}
}
func (self *requestBuffer) Init(elements []*clientRequest) {
self.elements = elements
self.start = 0
self.count = 0
}
/* clear all elements.*/
func (self *requestBuffer) Clear() {
self.start = 0
self.count = 0
}
func (self *requestBuffer) IsFull() bool {
return self.count == len(self.elements)
}
/* return true while size is 0, otherwise return false */
func (self *requestBuffer) IsEmpty() bool {
return 0 == self.count
}
/* Write an element, overwriting oldest element if buffer is full. App can
choose to avoid the overwrite by checking isFull(). */
func (self *requestBuffer) Push(elem *clientRequest) {
end := (self.start + self.count) % len(self.elements)
self.elements[end] = elem
if self.count == len(self.elements) {
self.start = (self.start + 1) % len(self.elements) /* full, overwrite */
} else {
self.count++
}
}
func (self *requestBuffer) Get(idx int) *clientRequest {
if self.IsEmpty() {
return nil
}
current := (self.start + idx) % len(self.elements)
return self.elements[current]
}
/* Read oldest element. App must ensure !isEmpty() first. */
func (self *requestBuffer) Pop() *clientRequest {
if self.IsEmpty() {
return nil
}
elem := self.elements[self.start]
self.start = (self.start + 1) % len(self.elements)
self.count--
return elem
}
func (self *requestBuffer) First() *clientRequest {
if self.IsEmpty() {
return nil
}
return self.elements[self.start]
}
func (self *requestBuffer) Last() *clientRequest {
if self.IsEmpty() {
return nil
}
end := (self.start + self.count - 1) % len(self.elements)
return self.elements[end]
}
/* Read all elements.*/
func (self *requestBuffer) Size() int {
return self.count
}
/* Read all elements.*/
func (self *requestBuffer) All() []*clientRequest {
if 0 == self.count {
return nil
}
res := make([]*clientRequest, 0, self.count)
if self.count <= (len(self.elements) - self.start) {
for i := self.start; i < (self.start + self.count); i++ {
res = append(res, self.elements[i])
}
return res
}
for i := self.start; i < len(self.elements); i++ {
res = append(res, self.elements[i])
}
for i := 0; len(res) < self.count; i++ {
res = append(res, self.elements[i])
}
return res
}