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LibreTranslate/app/app.py
Piero Toffanin ca1049f0d3 Merge main
2021-06-03 10:39:41 -04:00

578 lines
17 KiB
Python

import os
from functools import wraps
from flask import Flask, abort, jsonify, render_template, request
from flask_swagger import swagger
from flask_swagger_ui import get_swaggerui_blueprint
from app import flood
from app.language import detect_languages, transliterate
from .api_keys import Database
def get_json_dict(request):
d = request.get_json()
if not isinstance(d, dict):
abort(400, description="Invalid JSON format")
return d
def get_remote_address():
if request.headers.getlist("X-Forwarded-For"):
ip = request.headers.getlist("X-Forwarded-For")[0]
else:
ip = request.remote_addr or "127.0.0.1"
return ip
def get_req_limits(default_limit, api_keys_db, multiplier = 1):
req_limit = default_limit
if api_keys_db:
if request.is_json:
json = get_json_dict(request)
api_key = json.get("api_key")
else:
api_key = request.values.get("api_key")
if api_key:
db_req_limit = api_keys_db.lookup(api_key)
if db_req_limit is not None:
req_limit = db_req_limit
return req_limit
def get_routes_limits(default_req_limit, daily_req_limit, api_keys_db):
if default_req_limit == -1:
# TODO: better way?
default_req_limit = 9999999999999
def minute_limits():
return "%s per minute" % get_req_limits(default_req_limit, api_keys_db)
def daily_limits():
return "%s per day" % get_req_limits(daily_req_limit, api_keys_db, 1440)
res = [minute_limits]
if daily_req_limit > 0:
res.append(daily_limits)
return res
def create_app(args):
from app.init import boot
boot(args.load_only)
from app.language import languages
app = Flask(__name__)
if args.debug:
app.config["TEMPLATES_AUTO_RELOAD"] = True
# Map userdefined frontend languages to argos language object.
if args.frontend_language_source == "auto":
frontend_argos_language_source = type(
"obj", (object,), {"code": "auto", "name": "Auto Detect"}
)
else:
frontend_argos_language_source = next(
iter([l for l in languages if l.code == args.frontend_language_source]),
None,
)
frontend_argos_language_target = next(
iter([l for l in languages if l.code == args.frontend_language_target]), None
)
# Raise AttributeError to prevent app startup if user input is not valid.
if frontend_argos_language_source is None:
raise AttributeError(
f"{args.frontend_language_source} as frontend source language is not supported."
)
if frontend_argos_language_target is None:
raise AttributeError(
f"{args.frontend_language_target} as frontend target language is not supported."
)
api_keys_db = None
if args.req_limit > 0 or args.api_keys or args.daily_req_limit > 0:
api_keys_db = Database() if args.api_keys else None
from flask_limiter import Limiter
limiter = Limiter(
app,
key_func=get_remote_address,
default_limits=get_routes_limits(
args.req_limit, args.daily_req_limit, api_keys_db
),
)
else:
from .no_limiter import Limiter
limiter = Limiter()
if args.req_flood_threshold > 0:
flood.setup(args.req_flood_threshold)
def access_check(f):
@wraps(f)
def func(*a, **kw):
if flood.is_banned(get_remote_address()):
abort(403, description="Too many request limits violations")
if args.api_keys and args.require_api_key_origin:
if request.is_json:
json = get_json_dict(request)
ak = json.get("api_key")
else:
ak = request.values.get("api_key")
if (
api_keys_db.lookup(ak) is None and request.headers.get("Origin") != args.require_api_key_origin
):
abort(
403,
description="Please contact the server operator to obtain an API key",
)
return f(*a, **kw)
return func
@app.errorhandler(400)
def invalid_api(e):
return jsonify({"error": str(e.description)}), 400
@app.errorhandler(500)
def server_error(e):
return jsonify({"error": str(e.description)}), 500
@app.errorhandler(429)
def slow_down_error(e):
flood.report(get_remote_address())
return jsonify({"error": "Slowdown: " + str(e.description)}), 429
@app.errorhandler(403)
def denied(e):
return jsonify({"error": str(e.description)}), 403
@app.route("/")
@limiter.exempt
def index():
return render_template(
"index.html",
gaId=args.ga_id,
frontendTimeout=args.frontend_timeout,
api_keys=args.api_keys,
web_version=os.environ.get("LT_WEB") is not None,
)
@app.route("/javascript-licenses", methods=["GET"])
@limiter.exempt
def javascript_licenses():
return render_template("javascript-licenses.html")
@app.route("/languages", methods=["GET", "POST"])
@limiter.exempt
def langs():
"""
Retrieve list of supported languages
---
tags:
- translate
responses:
200:
description: List of languages
schema:
id: languages
type: array
items:
type: object
properties:
code:
type: string
description: Language code
name:
type: string
description: Human-readable language name (in English)
429:
description: Slow down
schema:
id: error-slow-down
type: object
properties:
error:
type: string
description: Reason for slow down
"""
return jsonify([{"code": l.code, "name": l.name} for l in languages])
# Add cors
@app.after_request
def after_request(response):
response.headers.add("Access-Control-Allow-Origin", "*")
response.headers.add(
"Access-Control-Allow-Headers", "Authorization, Content-Type"
)
response.headers.add("Access-Control-Expose-Headers", "Authorization")
response.headers.add("Access-Control-Allow-Methods", "GET, POST")
response.headers.add("Access-Control-Allow-Credentials", "true")
response.headers.add("Access-Control-Max-Age", 60 * 60 * 24 * 20)
return response
@app.route("/translate", methods=["POST"])
@access_check
def translate():
"""
Translate text from a language to another
---
tags:
- translate
parameters:
- in: formData
name: q
schema:
oneOf:
- type: string
example: Hello world!
- type: array
example: ['Hello world!']
required: true
description: Text(s) to translate
- in: formData
name: source
schema:
type: string
example: en
required: true
description: Source language code
- in: formData
name: target
schema:
type: string
example: es
required: true
description: Target language code
- in: formData
name: api_key
schema:
type: string
example: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
required: false
description: API key
responses:
200:
description: Translated text
schema:
id: translate
type: object
properties:
translatedText:
oneOf:
- type: string
- type: array
description: Translated text(s)
400:
description: Invalid request
schema:
id: error-response
type: object
properties:
error:
type: string
description: Error message
500:
description: Translation error
schema:
id: error-response
type: object
properties:
error:
type: string
description: Error message
429:
description: Slow down
schema:
id: error-slow-down
type: object
properties:
error:
type: string
description: Reason for slow down
403:
description: Banned
schema:
id: error-response
type: object
properties:
error:
type: string
description: Error message
"""
if request.is_json:
json = get_json_dict(request)
q = json.get("q")
source_lang = json.get("source")
target_lang = json.get("target")
else:
q = request.values.get("q")
source_lang = request.values.get("source")
target_lang = request.values.get("target")
if not q:
abort(400, description="Invalid request: missing q parameter")
if not source_lang:
abort(400, description="Invalid request: missing source parameter")
if not target_lang:
abort(400, description="Invalid request: missing target parameter")
batch = isinstance(q, list)
if batch and args.batch_limit != -1:
batch_size = len(q)
if args.batch_limit < batch_size:
abort(
400,
description="Invalid request: Request (%d) exceeds text limit (%d)"
% (batch_size, args.batch_limit),
)
if args.char_limit != -1:
if batch:
chars = sum([len(text) for text in q])
else:
chars = len(q)
if args.char_limit < chars:
abort(
400,
description="Invalid request: Request (%d) exceeds character limit (%d)"
% (chars, args.char_limit),
)
if source_lang == "auto":
candidate_langs = detect_languages(q)
if args.debug:
print(candidate_langs)
source_lang = candidate_langs[0]["language"]
if args.debug:
print("Auto detected: %s" % source_lang)
src_lang = next(iter([l for l in languages if l.code == source_lang]), None)
tgt_lang = next(iter([l for l in languages if l.code == target_lang]), None)
if src_lang is None:
abort(400, description="%s is not supported" % source_lang)
if tgt_lang is None:
abort(400, description="%s is not supported" % target_lang)
translator = src_lang.get_translation(tgt_lang)
try:
if batch:
return jsonify(
{
"translatedText": [
translator.translate(
transliterate(text, target_lang=source_lang)
)
for text in q
]
}
)
else:
return jsonify(
{
"translatedText": translator.translate(
transliterate(q, target_lang=source_lang)
)
}
)
except Exception as e:
abort(500, description="Cannot translate text: %s" % str(e))
@app.route("/detect", methods=["POST"])
@access_check
def detect():
"""
Detect the language of a single text
---
tags:
- translate
parameters:
- in: formData
name: q
schema:
type: string
example: Hello world!
required: true
description: Text to detect
- in: formData
name: api_key
schema:
type: string
example: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
required: false
description: API key
responses:
200:
description: Detections
schema:
id: detections
type: array
items:
type: object
properties:
confidence:
type: number
format: float
minimum: 0
maximum: 1
description: Confidence value
example: 0.6
language:
type: string
description: Language code
example: en
400:
description: Invalid request
schema:
id: error-response
type: object
properties:
error:
type: string
description: Error message
500:
description: Detection error
schema:
id: error-response
type: object
properties:
error:
type: string
description: Error message
429:
description: Slow down
schema:
id: error-slow-down
type: object
properties:
error:
type: string
description: Reason for slow down
403:
description: Banned
schema:
id: error-response
type: object
properties:
error:
type: string
description: Error message
"""
if flood.is_banned(get_remote_address()):
abort(403, description="Too many request limits violations")
if request.is_json:
json = get_json_dict(request)
q = json.get("q")
else:
q = request.values.get("q")
if not q:
abort(400, description="Invalid request: missing q parameter")
return jsonify(detect_languages(q))
@app.route("/frontend/settings")
@limiter.exempt
def frontend_settings():
"""
Retrieve frontend specific settings
---
tags:
- frontend
responses:
200:
description: frontend settings
schema:
id: frontend-settings
type: object
properties:
charLimit:
type: integer
description: Character input limit for this language (-1 indicates no limit)
frontendTimeout:
type: integer
description: Frontend translation timeout
language:
type: object
properties:
source:
type: object
properties:
code:
type: string
description: Language code
name:
type: string
description: Human-readable language name (in English)
target:
type: object
properties:
code:
type: string
description: Language code
name:
type: string
description: Human-readable language name (in English)
"""
return jsonify(
{
"charLimit": args.char_limit,
"frontendTimeout": args.frontend_timeout,
"language": {
"source": {
"code": frontend_argos_language_source.code,
"name": frontend_argos_language_source.name,
},
"target": {
"code": frontend_argos_language_target.code,
"name": frontend_argos_language_target.name,
},
},
}
)
swag = swagger(app)
swag["info"]["version"] = "1.2"
swag["info"]["title"] = "LibreTranslate"
@app.route("/spec")
@limiter.exempt
def spec():
return jsonify(swag)
SWAGGER_URL = "/docs" # URL for exposing Swagger UI (without trailing '/')
API_URL = "/spec"
# Call factory function to create our blueprint
swaggerui_blueprint = get_swaggerui_blueprint(SWAGGER_URL, API_URL)
app.register_blueprint(swaggerui_blueprint)
return app