Fastrq - Queue, Stack and Priority Queue built on Redis

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Fastrq for PHP

Features

• Abstract Queue, Deque, Capped Queue/Deque, and Overflow-able Capped Queue/Deque
• Abstract Stack, Capped Stack
• Abstract Priority Queue, Capped Priority Queue and Overflow-able Capped Priority Queue
• Push and Pop support batch operation
• Using Lua scripts to save RTT (Round Trip Time)
• Support getting indexes of members
• Support pushing only if a member not already inside the queue
• Support pushing only if the queue already exists/not already exist
• All operations are atomic

Requirements

• Redis >=3.0.2
• Python 2.7 or >=3.4

Installation

via pip

pip install fastrq

or from source

python setup.py install

Usage

from fastrq.queue import Queue, CappedQueue
from fastrq.deque import Deque
from fastrq.stack import Stack
from fastrq.priorityqueue import PriorityQueue

# queue
q = Queue("fastrq_queue")
q.push(1)
q.push([2, 3])
q.push_ni(1) # got [3, False]. `ni` stands for `not inside`
q.push_ae(1) # got 4. `ae` stands for `already exists`
q.push_ne(1) # got False. `ne` stands for `not already exist`
q.ttl(10)   # set the lifetime in seconds
q.range(0, -1)  # got ['1', '2', '3']
q.range(0, 1)  # got ['1', '2']
q.indexof_one(1); # got 0
q.indexof_one(2); # got 1
q.indexof_one(4); # got None
q.indexof_many([1, 2, 4]); # got {1: 0, 2: 1, 4: None}
# push only if the member not inside the queue
q.push_ni(4) # got [4, True]
q.pop()
q.pop(2)
q.destruct() # destruct the queue
cq = CappedQueue("fastrq_capped_queue", 3)
cq.push(1)
cq.push(2)
cq.push([3, 4]) # got "err_qof"
cq.push(3)
cq.push(4) # got "err_qf"
of_cq = OfCappedQueue("fastrq_of_capped_queue", 3)
of_cq.push(1)
of_cq.push([2, 3, 4])  # "1" would be forced out


# deque
dq = Deque("fastrq_deque")
dq.push_front([1, 2])
dq.push_back([3, 4])
dq.pop_front()
dq.pop_back()
dq.push_front_ni(3)
dq.push_back_ni(5)

# priority queue
pq = PriorityQueue("fastrq_priority_queue")
pq.push({'alibaba': 1})
pq.push({'google': 0, 'microsoft': 2})
pq.indexof_one('google'); # got 0
pq.indexof_one('alibaba'); # got 1
pq.indexof_one('baidu'); # got None
pq.pop()
pq.pop(2)
pq.push_ni('ibm', 4)
pq.push_ni('amazon', 5)

# stack
s = Stack("fastrq_stack")
s.push([1,2,3])
s.indexof_one(1); # got 2
s.indexof_one(2); # got 1
s.indexof_one(3); # got 0
s.pop()
s.push_ni(4)

Data types

Queue

• first in and first out
• unlimited capacity
• support batch push and batch pop

Deque

Derive from queue with more features

• support push front and push back
• support pop front and pop back

Capped Queue/Deque

Derive from queue/deque with more features

• Have fixed capacity
• Push to a full one would fail
• Push to one whose positions are not enough would fail

Overflow-able Capped Queue/Deque

Derive from capped queue/deque with more features

• The queue length would never exceed its capacity
• Push to an end would force out from the other end if one is full

Stack

• Last in and First out
• Unlimited capacity
• Support batch push and batch pop

Capped Stack

Derive from Stack with more features

• Have fixed capacity
• Push to a full capped stack would fail
• Push to a capped stack whose positions are not enough would fail

Priority Queue

• The lower the score, the higher the priority
• Unlimited capacity
• Support batch push and batch pop

Capped Priority Queue

Derive from Priority Queue with more features

• Have fixed capacity
• Push to a full one would fail
• Push to a capped one whose positions are not enough would fail

Overflow-able Capped Priority Queue

Derive from Capped Priority Queue with more features

• The queue length would never exceed its capacity
• Push to would force out the lowest priority if queue is full