Live streaming using videojs-record and videojs - python

I'm trying to make a video chat inside my application, and using videojs-record + videojs to do so. videojs-record to record the webcam (which is already working), and videojs to reproduce the video in the other side. By using the timestamp event, with the timeSlice property, I've managed to split the recorded video by each second.
this.player = videojs('#myVideo', this.options, () => {});
var player = this.player
var that = this
this.player.on('startRecord', () => {
that.segment = 0
});
player.on('timestamp', function() {
if (player.recordedData && player.recordedData.length > 0) {
var binaryData = player.recordedData[player.recordedData.length - 1]
that.$emit('dataVideoEvent', {video:binaryData, segment_index:that.segment})
that.segment += 1
}
});
So I've managed to upload the said segments to Amazon's S3, and have used a Python endpoint to return a HLS file containing the uploaded files:
duration = 1
totalDuration = len(list)
string = ('#EXTM3U\n'
'#EXT-X-PLAYLIST-TYPE:EVENT\n'
'#EXT-X-TARGETDURATION:3600\n'
'#EXT-X-VERSION:3\n'
'#EXT-X-MEDIA-SEQUENCE:0\n')
ended = False
now = datetime.utcnow().replace(tzinfo=pytz.utc)
for index, obj in enumerate(list):
url = {retrieving url based in obj}
string += '#EXTINF:{duration}, no desc\n{url}\n'.format(duration=duration, url=url)
ended = (obj.created_at.replace(tzinfo=pytz.utc) + timedelta(seconds=10)) < now
if ended:
string += '#EXT-X-ENDLIST'
Although, that HLS file isn't working. The videojs player shows the proper full time of the video, but never starts to play it, and logs no errors. If I try to reproduce the video using Bitmovin's player demo, it says SOURCE_MANIFEST_INVALID.
I've also tried to create a XML+DASH file instead of a HLS one, but it didn't work as well. And I've also tried to change the videojs-record videoMimeType property to other values, like video/webm;codecs=vp8,opus or video/mp2t;codecs=vp8,opus, but it also didn't change a thing.
Also, the #action that returns the HLS file has a renderer_classes property using that renderer:
class HLSRenderer(BaseRenderer):
media_type = 'application/x-mpegurl'
format = 'm3u8'
level_sep = '.'
header = None
labels = None
writer_opts = None
def render(self, data, media_type=None, renderer_context={}, writer_opts=None):
return data
And at last, I've configured CORS in that way in S3, in case that's relevant:
<?xml version="1.0" encoding="UTF-8"?>
<CORSConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/">
<CORSRule>
<AllowedOrigin>*</AllowedOrigin>
<AllowedMethod>GET</AllowedMethod>
<AllowedMethod>HEAD</AllowedMethod>
<MaxAgeSeconds>3000</MaxAgeSeconds>
<AllowedHeader>Range</AllowedHeader>
</CORSRule>
</CORSConfiguration>
And by the way, the #action is usually blocked so only the expected user can see it, but at this moment I've changed its permission_classes value to AllowAny, so I can test in websites like Bitmovin.
What exactly am I doing wrong?

I gave up and ended up using Jitsi instead of videojs-record. I had to run it with an iframe within Vue, but it succeed where all the rest failed.
I've spent the last 18 days trying to make a live stream by myself, when I could make Jitsi work with my project in almost one single night. I recommend their Docker, it's pretty easy to set up.
https://github.com/jitsi/docker-jitsi-meet

Related

Using python and suds, data not read by server side because element is not defined as an array

I am a very inexperienced programmer with no formal education. Details will be extremely helpful in any responses.
I have made several basic python scripts to call SOAP APIs, but I am running into an issue with a specific API function that has an embedded array.
Here is a sample excerpt from a working XML format to show nested data:
<bomData xsi:type="urn:inputBOM" SOAP-ENC:arrayType="urn:bomItem[]">
<bomItem>
<item_partnum></item_partnum>
<item_partrev></item_partrev>
<item_serial></item_serial>
<item_lotnum></item_lotnum>
<item_sublotnum></item_sublotnum>
<item_qty></item_qty>
</bomItem>
<bomItem>
<item_partnum></item_partnum>
<item_partrev></item_partrev>
<item_serial></item_serial>
<item_lotnum></item_lotnum>
<item_sublotnum></item_sublotnum>
<item_qty></item_qty>
</bomItem>
</bomData>
I have tried 3 different things to get this to work to no avail.
I can generate the near exact XML from my script, but a key attribute missing is the 'SOAP-ENC:arrayType="urn:bomItem[]"' in the above XML example.
Option 1 was using MessagePlugin, but I get an error because my section is like the 3 element and it always injects into the first element. I have tried body[2], but this throws an error.
Option 2 I am trying to create the object(?). I read a lot of stack overflow, but I might be missing something for this.
Option 3 looked simple enough, but also failed. I tried setting the values in the JSON directly. I got these examples by an XML sample to JSON.
I have also done a several other minor things to try to get it working, but not worth mentioning. Although, if there is a way to somehow do the following, then I'm all ears:
bomItem[]: bomData = {"bomItem"[{...,...,...}]}
Here is a sample of my script:
# for python 3
# using pip install suds-py3
from suds.client import Client
from suds.plugin import MessagePlugin
# Config
#option 1: trying to set it as an array using plugin
class MyPlugin(MessagePlugin):
def marshalled(self, context):
body = context.envelope.getChild('Body')
bomItem = body[0]
bomItem.set('SOAP-ENC:arrayType', 'urn:bomItem[]')
URL = "http://localhost/application/soap?wsdl"
client = Client(URL, plugins=[MyPlugin()])
transact_info = {
"username":"",
"transaction":"",
"workorder":"",
"serial":"",
"trans_qty":"",
"seqnum":"",
"opcode":"",
"warehouseloc":"",
"warehousebin":"",
"machine_id":"",
"comment":"",
"defect_code":""
}
#WIP - trying to get bomData below working first
inputData = {
"dataItem":[
{
"fieldname": "",
"fielddata": ""
}
]
}
#option 2: trying to create the element here and define as an array
#inputbom = client.factory.create('ns3:inputBOM')
#inputbom._type = "SOAP-ENC:arrayType"
#inputbom.value = "urn:bomItem[]"
bomData = {
#Option 3: trying to set the time and array type in JSON
#"#xsi:type":"urn:inputBOM",
#"#SOAP-ENC:arrayType":"urn:bomItem[]",
"bomItem":[
{
"item_partnum":"",
"item_partrev":"",
"item_serial":"",
"item_lotnum":"",
"item_sublotnum":"",
"item_qty":""
},
{
"item_partnum":"",
"item_partrev":"",
"item_serial":"",
"item_lotnum":"",
"item_sublotnum":"",
"item_qty":""
}
]
}
try:
response = client.service.transactUnit(transact_info,inputData,bomData)
print("RESPONSE: ")
print(response)
#print(client)
#print(envelope)
except Exception as e:
#handle error here
print(e)
I appreciate any help and hope it is easy to solve.
I have found the answer I was looking for. At least a working solution.
In any case, option 1 worked out. I read up on it at the following link:
https://suds-py3.readthedocs.io/en/latest/
You can review at the '!MessagePlugin' section.
I found a solution to get message plugin working from the following post:
unmarshalling Error: For input string: ""
A user posted an example how to crawl through the XML structure and modify it.
Here is my modified example to get my script working:
#Using MessagePlugin to modify elements before sending to server
class MyPlugin(MessagePlugin):
# created method that could be reused to modify sections with similar
# structure/requirements
def addArrayType(self, dataType, arrayType, transactUnit):
# this is the code that is key to crawling through the XML - I get
# the child of each parent element until I am at the right level for
# modification
data = transactUnit.getChild(dataType)
if data:
data.set('SOAP-ENC:arrayType', arrayType)
def marshalled(self, context):
# Alter the envelope so that the xsd namespace is allowed
context.envelope.nsprefixes['xsd'] = 'http://www.w3.org/2001/XMLSchema'
body = context.envelope.getChild('Body')
transactUnit = body.getChild("transactUnit")
if transactUnit:
self.addArrayType('inputData', 'urn:dataItem[]', transactUnit)
self.addArrayType('bomData', 'urn:bomItem[]', transactUnit)

Google Document Ai giving different outputs for the same file

I was using Document OCR API to extract text from a pdf file, but part of it is not accurate. I found that the reason may be due to the existence of some Chinese characters.
The following is a made-up example in which I cropped part of the region that the extracted text is wrong and add some Chinese characters to reproduce the problem.
When I use the website version, I cannot get the Chinese characters but the remaining characters are correct.
When I use Python to extract the text, I can get the Chinese characters correctly but part of the remaining characters are wrong.
The actual string that I got.
Are the versions of Document AI in the website and API different? How can I get all the characters correctly?
Update:
When I print the detected_languages (don't know why for lines = page.lines, the detected_languages for both lines are empty list, need to change to page.blocks or page.paragraphs first) after printing the text, I get the following output.
Code:
from google.cloud import documentai_v1beta3 as documentai
project_id= 'secret-medium-xxxxxx'
location = 'us' # Format is 'us' or 'eu'
processor_id = 'abcdefg123456' # Create processor in Cloud Console
opts = {}
if location == "eu":
opts = {"api_endpoint": "eu-documentai.googleapis.com"}
client = documentai.DocumentProcessorServiceClient(client_options=opts)
def get_text(doc_element: dict, document: dict):
"""
Document AI identifies form fields by their offsets
in document text. This function converts offsets
to text snippets.
"""
response = ""
# If a text segment spans several lines, it will
# be stored in different text segments.
for segment in doc_element.text_anchor.text_segments:
start_index = (
int(segment.start_index)
if segment in doc_element.text_anchor.text_segments
else 0
)
end_index = int(segment.end_index)
response += document.text[start_index:end_index]
return response
def get_lines_of_text(file_path: str, location: str = location, processor_id: str = processor_id, project_id: str = project_id):
# You must set the api_endpoint if you use a location other than 'us', e.g.:
# opts = {}
# if location == "eu":
# opts = {"api_endpoint": "eu-documentai.googleapis.com"}
# The full resource name of the processor, e.g.:
# projects/project-id/locations/location/processor/processor-id
# You must create new processors in the Cloud Console first
name = f"projects/{project_id}/locations/{location}/processors/{processor_id}"
# Read the file into memory
with open(file_path, "rb") as image:
image_content = image.read()
document = {"content": image_content, "mime_type": "application/pdf"}
# Configure the process request
request = {"name": name, "raw_document": document}
result = client.process_document(request=request)
document = result.document
document_pages = document.pages
response_text = []
# For a full list of Document object attributes, please reference this page: https://googleapis.dev/python/documentai/latest/_modules/google/cloud/documentai_v1beta3/types/document.html#Document
# Read the text recognition output from the processor
print("The document contains the following paragraphs:")
for page in document_pages:
lines = page.blocks
for line in lines:
block_text = get_text(line.layout, document)
confidence = line.layout.confidence
response_text.append((block_text[:-1] if block_text[-1:] == '\n' else block_text, confidence))
print(f"Text: {block_text}")
print("Detected Language", line.detected_languages)
return response_text
if __name__ == '__main__':
print(get_lines_of_text('/pdf path'))
It seems the language code is wrong, will this affect the result?
Posting this Community Wiki for better visibility.
One of features of DocumentAI is OCR - Optical Character Recognition which allows recognizing text from various files.
OP in this scenario received difference outputs using Try it function and Client Libraries - Python.
Why are there discrepancies between Try it and Python library?
It's hard to say as both methods use the same API documentai_v1beta3. It might be related to some files modifications when pdf is uploading to Try it Demo, different endpoints, language alphabet recognition or some random stuff.
When you are using Python Client you also get accuracy % of text identification. Below examples from my testes:
However, OP's identification is about 0,73 so it might get wrong results and in this situation is a visible issue. I guess it cannot be anyhow improved using code. Maybe if there would be different quality of PDF (in shown OPs example there are some dots which might affect identification).

Downloading Multiple torrent files with Libtorrent in Python

I'm trying to write a torrent application that can take in a list of magnet links and then download them all together. I've been trying to read and understand the documentation at Libtorrent but I haven't been able to tell if what I try works or not. I've managed to be able to apply a SOCKS5 proxy to a Libtorrent session and download a single magnet link using this code:
import libtorrent as lt
import time
import os
ses = lt.session()
r = lt.proxy_settings()
r.hostname = "proxy_info"
r.username = "proxy_info"
r.password = "proxy_info"
r.port = 1080
r.type = lt.proxy_type_t.socks5_pw
ses.set_peer_proxy(r)
ses.set_web_seed_proxy(r)
ses.set_proxy(r)
t = ses.settings()
t.force_proxy = True
t.proxy_peer_connections = True
t.anonymous_mode = True
ses.set_settings(t)
print(ses.get_settings())
ses.peer_proxy()
ses.web_seed_proxy()
ses.set_settings(t)
magnet_link = "magnet"
params = {
"save_path": os.getcwd() + r"\torrents",
"storage_mode": lt.storage_mode_t.storage_mode_sparse,
"url": magnet_link
}
handle = lt.add_magnet_uri(ses, magnet_link, params)
ses.start_dht()
print('downloading metadata...')
while not handle.has_metadata():
time.sleep(1)
print('got metadata, starting torrent download...')
while handle.status().state != lt.torrent_status.seeding:
s = handle.status()
state_str = ['queued', 'checking', 'downloading metadata', 'downloading', 'finished', 'seeding', 'allocating']
print('%.2f%% complete (down: %.1f kb/s up: %.1f kB/s peers: %d) %s' % (s.progress * 100, s.download_rate / 1000, s.upload_rate / 1000, s.num_peers, state_str[s.state]))
time.sleep(5)
This is great and all for runing on its own with a single link. What I want to do is something like this:
def torrent_download(magnetic_link_list):
for mag in range(len(magnetic_link_list)):
handle = lt.add_magnet_uri(ses, magnetic_link_list[mag], params)
#Then download all the files
#Once all files complete, stop the torrents so they dont seed.
return torrent_name_list
I'm not sure if this is even on the right track or not, but some pointers would be helpful.
UPDATE: This is what I now have and it works fine in my case
def magnet2torrent(magnet_link):
global LIBTORRENT_SESSION, TORRENT_HANDLES
if LIBTORRENT_SESSION is None and TORRENT_HANDLES is None:
TORRENT_HANDLES = []
settings = lt.default_settings()
settings['proxy_hostname'] = CONFIG_DATA["PROXY"]["HOST"]
settings['proxy_username'] = CONFIG_DATA["PROXY"]["USERNAME"]
settings['proxy_password'] = CONFIG_DATA["PROXY"]["PASSWORD"]
settings['proxy_port'] = CONFIG_DATA["PROXY"]["PORT"]
settings['proxy_type'] = CONFIG_DATA["PROXY"]["TYPE"]
settings['force_proxy'] = True
settings['anonymous_mode'] = True
LIBTORRENT_SESSION = lt.session(settings)
params = {
"save_path": os.getcwd() + r"/torrents",
"storage_mode": lt.storage_mode_t.storage_mode_sparse,
"url": magnet_link
}
TORRENT_HANDLES.append(LIBTORRENT_SESSION.add_torrent(params))
def check_torrents():
global TORRENT_HANDLES
for torrent in range(len(TORRENT_HANDLES)):
print(TORRENT_HANDLES[torrent].status().is_seeding)
It's called "magnet links" (not magnetic).
In new versions of libtorrent, the way you add a magnet link is:
params = lt.parse_magnet_link(uri)
handle = ses.add_torrent(params)
That also gives you an opportunity to tweak the add_torrent_params object, to set the save directory for instance.
If you're adding a lot of magnet links (or regular torrent files for that matter) and want to do it quickly, a faster way is to use:
ses.add_torrent_async(params)
That function will return immediately and the torrent_handle object can be picked up later in the add_torrent_alert.
As for downloading multiple magnet links in parallel, your pseudo code for adding them is correct. You just want to make sure you either save off all the torrent_handle objects you get back or query all torrent handles once you're done adding them (using ses.get_torrents()). In your pseudo code you seem to overwrite the last torrent handle every time you add a new one.
The condition you expressed for exiting was that all torrents were complete. The simplest way of doing that is simply to poll them all with handle.status().is_seeding. i.e. loop over your list of torrent handles and ask that. Keep in mind that the call to status() requires a round-trip to the libtorrent network thread, which isn't super fast.
The faster way of doing this is to keep track of all torrents that aren't seeding yet, and "strike them off your list" as you get torrent_finished_alerts for torrents. (you get alerts by calling ses.pop_alerts()).
Another suggestion I would make is to set up your settings_pack object first, then create the session. It's more efficient and a bit cleaner. Especially with regards to opening listen sockets and then immediately closing and re-opening them when you change settings.
i.e.
p = lt.settings_pack()
p['proxy_hostname'] = '...'
p['proxy_username'] = '...'
p['proxy_password'] = '...'
p['proxy_port'] = 1080
p['proxy_type'] = lt.proxy_type_t.socks5_pw
p['proxy_peer_connections'] = True
ses = lt.session(p)

Django/Python - check if the user uploads a file - if not, show an image

I have an input tag where the user has to upload a file. Right now if the user doesn't upload anything I do this in the main view:
if len(request.FILES) != 0:
data = request.FILES['some_file']
...do some work...
else:
return render(request, 'App/nofile.html' )
If there is no file I take the user the another page where it says that no file was uploaded and make him/her go back to the main page.
Is there a way that I can check if the user did not uploaded a file and not go to another page just show a PICTURE in the middle of the screen in that main page with the message?
NOT JUST A STRING MESSAGE, a picture with the message.
Maybe javascript is the answer but I know nothing about javascript.
Thanks in advance for any help.
There are two ways:
1) If you do validation on server side just like you do right now. It seems that you do it right, but you should use redirect instead of render if you handle POST data:
if len(request.FILES) != 0:
data = request.FILES['some_file']
...do some work...
else:
return redirect('/nofile/' {'foo': bar})
2) If you want client-side validation. Then you must prevent default submit action by javascript and check if file length equals 0. You can check this question or use this jQuery snippet:
$('form').submit(function(event){
validated = true;
if ($('#some_file_input').get(0).files.length === 0) {
validated = false;
console.log("No files selected.");
// Or some div with image showing
}
if (validated != true) {
event.preventDefault();
}
});

Delete all data for a kind in Google App Engine

I would like to wipe out all data for a specific kind in Google App Engine. What is the
best way to do this?
I wrote a delete script (hack), but since there is so much data is
timeout's out after a few hundred records.
I am currently deleting the entities by their key, and it seems to be faster.
from google.appengine.ext import db
class bulkdelete(webapp.RequestHandler):
def get(self):
self.response.headers['Content-Type'] = 'text/plain'
try:
while True:
q = db.GqlQuery("SELECT __key__ FROM MyModel")
assert q.count()
db.delete(q.fetch(200))
time.sleep(0.5)
except Exception, e:
self.response.out.write(repr(e)+'\n')
pass
from the terminal, I run curl -N http://...
You can now use the Datastore Admin for that: https://developers.google.com/appengine/docs/adminconsole/datastoreadmin#Deleting_Entities_in_Bulk
If I were a paranoid person, I would say Google App Engine (GAE) has not made it easy for us to remove data if we want to. I am going to skip discussion on index sizes and how they translate a 6 GB of data to 35 GB of storage (being billed for). That's another story, but they do have ways to work around that - limit number of properties to create index on (automatically generated indexes) et cetera.
The reason I decided to write this post is that I need to "nuke" all my Kinds in a sandbox. I read about it and finally came up with this code:
package com.intillium.formshnuker;
import java.io.IOException;
import java.util.ArrayList;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.google.appengine.api.datastore.Key;
import com.google.appengine.api.datastore.Query;
import com.google.appengine.api.datastore.Entity;
import com.google.appengine.api.datastore.FetchOptions;
import com.google.appengine.api.datastore.DatastoreService;
import com.google.appengine.api.datastore.DatastoreServiceFactory;
import com.google.appengine.api.labs.taskqueue.QueueFactory;
import com.google.appengine.api.labs.taskqueue.TaskOptions.Method;
import static com.google.appengine.api.labs.taskqueue.TaskOptions.Builder.url;
#SuppressWarnings("serial")
public class FormsnukerServlet extends HttpServlet {
public void doGet(final HttpServletRequest request, final HttpServletResponse response) throws IOException {
response.setContentType("text/plain");
final String kind = request.getParameter("kind");
final String passcode = request.getParameter("passcode");
if (kind == null) {
throw new NullPointerException();
}
if (passcode == null) {
throw new NullPointerException();
}
if (!passcode.equals("LONGSECRETCODE")) {
response.getWriter().println("BAD PASSCODE!");
return;
}
System.err.println("*** deleting entities form " + kind);
final long start = System.currentTimeMillis();
int deleted_count = 0;
boolean is_finished = false;
final DatastoreService dss = DatastoreServiceFactory.getDatastoreService();
while (System.currentTimeMillis() - start < 16384) {
final Query query = new Query(kind);
query.setKeysOnly();
final ArrayList<Key> keys = new ArrayList<Key>();
for (final Entity entity: dss.prepare(query).asIterable(FetchOptions.Builder.withLimit(128))) {
keys.add(entity.getKey());
}
keys.trimToSize();
if (keys.size() == 0) {
is_finished = true;
break;
}
while (System.currentTimeMillis() - start < 16384) {
try {
dss.delete(keys);
deleted_count += keys.size();
break;
} catch (Throwable ignore) {
continue;
}
}
}
System.err.println("*** deleted " + deleted_count + " entities form " + kind);
if (is_finished) {
System.err.println("*** deletion job for " + kind + " is completed.");
} else {
final int taskcount;
final String tcs = request.getParameter("taskcount");
if (tcs == null) {
taskcount = 0;
} else {
taskcount = Integer.parseInt(tcs) + 1;
}
QueueFactory.getDefaultQueue().add(
url("/formsnuker?kind=" + kind + "&passcode=LONGSECRETCODE&taskcount=" + taskcount).method(Method.GET));
System.err.println("*** deletion task # " + taskcount + " for " + kind + " is queued.");
}
response.getWriter().println("OK");
}
}
I have over 6 million records. That's a lot. I have no idea what the cost will be to delete the records (maybe more economical not to delete them). Another alternative would be to request a deletion for the entire application (sandbox). But that's not realistic in most cases.
I decided to go with smaller groups of records (in easy query). I know I could go for 500 entities, but then I started receiving very high rates of failure (re delete function).
My request from GAE team: please add a feature to delete all entities of a kind in a single transaction.
Presumably your hack was something like this:
# Deleting all messages older than "earliest_date"
q = db.GqlQuery("SELECT * FROM Message WHERE create_date < :1", earliest_date)
results = q.fetch(1000)
while results:
db.delete(results)
results = q.fetch(1000, len(results))
As you say, if there's sufficient data, you're going to hit the request timeout before it gets through all the records. You'd have to re-invoke this request multiple times from outside to ensure all the data was erased; easy enough to do, but hardly ideal.
The admin console doesn't seem to offer any help, as (from my own experience with it), it seems to only allow entities of a given type to be listed and then deleted on a page-by-page basis.
When testing, I've had to purge my database on startup to get rid of existing data.
I would infer from this that Google operates on the principle that disk is cheap, and so data is typically orphaned (indexes to redundant data replaced), rather than deleted. Given there's a fixed amount of data available to each app at the moment (0.5 GB), that's not much help for non-Google App Engine users.
Try using App Engine Console then you dont even have to deploy any special code
I've tried db.delete(results) and App Engine Console, and none of them seems to be working for me. Manually removing entries from Data Viewer (increased limit up to 200) didn't work either since I have uploaded more than 10000 entries. I ended writing this script
from google.appengine.ext import db
from google.appengine.ext import webapp
from google.appengine.ext.webapp.util import run_wsgi_app
import wsgiref.handlers
from mainPage import YourData #replace this with your data
class CleanTable(webapp.RequestHandler):
def get(self, param):
txt = self.request.get('table')
q = db.GqlQuery("SELECT * FROM "+txt)
results = q.fetch(10)
self.response.headers['Content-Type'] = 'text/plain'
#replace yourapp and YouData your app info below.
self.response.out.write("""
<html>
<meta HTTP-EQUIV="REFRESH" content="5; url=http://yourapp.appspot.com/cleanTable?table=YourData">
<body>""")
try:
for i in range(10):
db.delete(results)
results = q.fetch(10, len(results))
self.response.out.write("<p>10 removed</p>")
self.response.out.write("""
</body>
</html>""")
except Exception, ints:
self.response.out.write(str(inst))
def main():
application = webapp.WSGIApplication([
('/cleanTable(.*)', CleanTable),
])
wsgiref.handlers.CGIHandler().run(application)
The trick was to include redirect in html instead of using self.redirect. I'm ready to wait overnight to get rid of all the data in my table. Hopefully, GAE team will make it easier to drop tables in the future.
The official answer from Google is that you have to delete in chunks spread over multiple requests. You can use AJAX, meta refresh, or request your URL from a script until there are no entities left.
The fastest and efficient way to handle bulk delete on Datastore is by using the new mapper API announced on the latest Google I/O.
If your language of choice is Python, you just have to register your mapper in a mapreduce.yaml file and define a function like this:
from mapreduce import operation as op
def process(entity):
yield op.db.Delete(entity)
On Java you should have a look to this article that suggests a function like this:
#Override
public void map(Key key, Entity value, Context context) {
log.info("Adding key to deletion pool: " + key);
DatastoreMutationPool mutationPool = this.getAppEngineContext(context)
.getMutationPool();
mutationPool.delete(value.getKey());
}
One tip. I suggest you get to know the remote_api for these types of uses (bulk deleting, modifying, etc.). But, even with the remote api, batch size can be limited to a few hundred at a time.
Unfortunately, there's no way to easily do a bulk delete. Your best bet is to write a script that deletes a reasonable number of entries per invocation, and then call it repeatedly - for example, by having your delete script return a 302 redirect whenever there's more data to delete, then fetching it with "wget --max-redirect=10000" (or some other large number).
With django, setup url:
url(r'^Model/bdelete/$', v.bulk_delete_models, {'model':'ModelKind'}),
Setup view
def bulk_delete_models(request, model):
import time
limit = request.GET['limit'] or 200
start = time.clock()
set = db.GqlQuery("SELECT __key__ FROM %s" % model).fetch(int(limit))
count = len(set)
db.delete(set)
return HttpResponse("Deleted %s %s in %s" % (count,model,(time.clock() - start)))
Then run in powershell:
$client = new-object System.Net.WebClient
$client.DownloadString("http://your-app.com/Model/bdelete/?limit=400")
If you are using Java/JPA you can do something like this:
em = EntityManagerFactoryUtils.getTransactionalEntityManager(entityManagerFactory)
Query q = em.createQuery("delete from Table t");
int number = q.executeUpdate();
Java/JDO info can be found here: http://code.google.com/appengine/docs/java/datastore/queriesandindexes.html#Delete_By_Query
Yes you can:
Go to Datastore Admin, and then select the Entitiy type you want to delete and click Delete.
Mapreduce will take care of deleting!
On a dev server, one can cd to his app's directory then run it like this:
dev_appserver.py --clear_datastore=yes .
Doing so will start the app and clear the datastore. If you already have another instance running, the app won't be able to bind to the needed IP and therefore fail to start...and to clear your datastore.
You can use the task queues to delete chunks of say 100 objects.
Deleting objects in GAE shows how limited the Admin capabilities are in GAE. You have to work with batches on 1000 entities or less. You can use the bulkloader tool that works with csv's but the documentation does not cover java.
I am using GAE Java and my strategy for deletions involves having 2 servlets, one for doing the actually delete and another to load the task queues. When i want to do a delete, I run the queue loading servlet, it loads the queues and then GAE goes to work executing all the tasks in the queue.
How to do it:
Create a servlet that deletes a small number of objects.
Add the servlet to your task queues.
Go home or work on something else ;)
Check the datastore every so often ...
I have a datastore with about 5000 objects that i purge every week and it takes about 6 hours to clean out, so i run the task on Friday night.
I use the same technique to bulk load my data which happens to be about 5000 objects, with about a dozen properties.
This worked for me:
class ClearHandler(webapp.RequestHandler):
def get(self):
self.response.headers['Content-Type'] = 'text/plain'
q = db.GqlQuery("SELECT * FROM SomeModel")
self.response.out.write("deleting...")
db.delete(q)
Thank you all guys, I got what I need. :D
This may be useful if you have lots db models to delete, you can dispatch it in your terminal. And also, you can manage the delete list in DB_MODEL_LIST yourself.
Delete DB_1:
python bulkdel.py 10 DB_1
Delete All DB:
python bulkdel.py 11
Here is the bulkdel.py file:
import sys, os
URL = 'http://localhost:8080'
DB_MODEL_LIST = ['DB_1', 'DB_2', 'DB_3']
# Delete Model
if sys.argv[1] == '10' :
command = 'curl %s/clear_db?model=%s' % ( URL, sys.argv[2] )
os.system( command )
# Delete All DB Models
if sys.argv[1] == '11' :
for model in DB_MODEL_LIST :
command = 'curl %s/clear_db?model=%s' % ( URL, model )
os.system( command )
And here is the modified version of alexandre fiori's code.
from google.appengine.ext import db
class DBDelete( webapp.RequestHandler ):
def get( self ):
self.response.headers['Content-Type'] = 'text/plain'
db_model = self.request.get('model')
sql = 'SELECT __key__ FROM %s' % db_model
try:
while True:
q = db.GqlQuery( sql )
assert q.count()
db.delete( q.fetch(200) )
time.sleep(0.5)
except Exception, e:
self.response.out.write( repr(e)+'\n' )
pass
And of course, you should map the link to model in a file(like main.py in GAE), ;)
In case some guys like me need it in detail, here is part of main.py:
from google.appengine.ext import webapp
import utility # DBDelete was defined in utility.py
application = webapp.WSGIApplication([('/clear_db',utility.DBDelete ),('/',views.MainPage )],debug = True)
To delete all entities in a given kind in Google App Engine you only need to do as follows:
from google.cloud import datastore
query = datastore.Client().query(kind = <KIND>)
results = query.fetch()
for result in results:
datastore.Client().delete(result.key)
In javascript, the following will delete all the entries for on page:
document.getElementById("allkeys").checked=true;
checkAllEntities();
document.getElementById("delete_button").setAttribute("onclick","");
document.getElementById("delete_button").click();
given that you are on the admin-page (.../_ah/admin) with the entities you want to delete.

Categories

Resources