FROM python:alpine

LABEL maintainer="feiskyer@gmail.com"

RUN pip install flask

EXPOSE 80

ADD app.py /app.py

CMD ["python", "/app.py"]

.PHONY: run

run:

docker run --name=app -p 10000:80 -itd feisky/word-pop

.PHONY: build

build:

docker build -t feisky/word-pop -f Dockerfile .

.PHONY: push

push:

docker push feisky/word-pop

.PHONY: clean

clean:

docker rm -f app

**《[Linux 性能优化实战](https://time.geekbang.org/column/intro/140)》第 xx 篇案例。**

案例场景：

* 简单的 flask app，提供一个测试单词热度的 api。该接口会生成一批文章并分别保存到一个文件中，再逐个读取这些文件来统计目标的单词是否出现在文章中

* 应用程序接口的性能并不让人满意，I/O 延迟过大

make build

make run

运行后，访问 `http://<ip-address>/popularity/<word>` 就可以测试单词的热度。

make clean

import os

import uuid

import random

import shutil

from concurrent.futures import ThreadPoolExecutor

from flask import Flask, jsonify

app = Flask(__name__)

def validate(word, sentence):

return word in sentence

def generate_article():

s_nouns = [

"A dude", "My mom", "The king", "Some guy", "A cat with rabies",

"A sloth", "Your homie", "This cool guy my gardener met yesterday",

"Superman"

]

p_nouns = [

"These dudes", "Both of my moms", "All the kings of the world",

"Some guys", "All of a cattery's cats",

"The multitude of sloths living under your bed", "Your homies",

"Like, these, like, all these people", "Supermen"

]

s_verbs = [

"eats", "kicks", "gives", "treats", "meets with", "creates", "hacks",

"configures", "spies on", "retards", "meows on", "flees from",

"tries to automate", "explodes"

]

infinitives = [

"to make a pie.", "for no apparent reason.",

"because the sky is green.", "for a disease.",

"to be able to make toast explode.", "to know more about archeology."

]

sentence = '{} {} {} {}'.format(

random.choice(s_nouns), random.choice(s_verbs),

random.choice(s_nouns).lower() or random.choice(p_nouns).lower(),

random.choice(infinitives))

return '\n'.join([sentence for i in range(50000)])

def hello_world():

return 'hello world'

def word_popularity(word):

dir_path = '/tmp/{}'.format(uuid.uuid1())

count = 0

sample_size = 1000

def save_to_file(file_name, content):

with open(file_name, 'w') as f:

f.write(content)

try:

# initial directory firstly

os.mkdir(dir_path)

# save article to files

for i in range(sample_size):

file_name = '{}/{}.txt'.format(dir_path, i)

article = generate_article()

save_to_file(file_name, article)

# count word popularity

for root, dirs, files in os.walk(dir_path):

for file_name in files:

with open('{}/{}'.format(dir_path, file_name)) as f:

if validate(word, f.read()):

count += 1

finally:

# clean files

shutil.rmtree(dir_path, ignore_errors=True)

return jsonify({'popularity': count / sample_size * 100, 'word': word})

def word_popular(word):

count = 0

sample_size = 1000

articles = []

try:

for i in range(sample_size):

articles.append(generate_article())

for article in articles:

if validate(word, article):

count += 1

finally:

pass

return jsonify({'popularity': count / sample_size * 100, 'word': word})

if __name__ == '__main__':

app.run(debug=True, host='0.0.0.0', port=80)