I'm using ANTLRT to parse expressions. When I add following rule, ANTLR runs out of memory (pls see log snippet at the end).
comp_expr returns [ AbstractLogicalExpression expr ]:
expr1=or_type_expr LOG_LT expr2=or_type_expr { $expr = BinaryLogExpr.create( BinaryLogExpr.OP_TYPE.LT,
$expr1.expr, $expr2.expr ); } |
expr1=or_type_expr LOG_GT expr2=or_type_expr { $expr = BinaryLogExpr.create( BinaryLogExpr.OP_TYPE.GT,
$expr1.expr, $expr2.expr ); } |
or_type_expr { $expr = $or_type_expr.expr; };
Similar rules around (e.g. or_type_expr) in the same grammar work just fine. LOG_LT and LOG_GT are currently defined as following:
LOG_GT: '>>';
LOG_LT: '<<';
However, I tried other char sequences (like '.LT.' and '.GT' accordingly) but the effect is the same.
The only way to put it back to work is to comment-out the entire alternates containing LOG_LT and LOG_GT.
Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
at org.antlr.v4.runtime.atn.ArrayPredictionContext.<init>(ArrayPredictionContext.java:48)
at org.antlr.v4.runtime.atn.PredictionContext.merge(PredictionContext.java:195)
at org.antlr.v4.runtime.atn.PredictionContext.mergeArrays(PredictionContext.java:418)
at org.antlr.v4.runtime.atn.PredictionContext.merge(PredictionContext.java:197)
at org.antlr.v4.runtime.atn.PredictionContext.mergeArrays(PredictionContext.java:418)
at org.antlr.v4.runtime.atn.PredictionContext.merge(PredictionContext.java:197)
at org.antlr.v4.runtime.atn.ATNConfigSet.add(ATNConfigSet.java:178)
at org.antlr.v4.runtime.atn.ParserATNSimulator.closure_(ParserATNSimulator.java:1551)
at org.antlr.v4.runtime.atn.ParserATNSimulator.closureCheckingStopState(ParserATNSimulator.java:1535)
at org.antlr.v4.runtime.atn.ParserATNSimulator.closure_(ParserATNSimulator.java:1603)
at org.antlr.v4.runtime.atn.ParserATNSimulator.closureCheckingStopState(ParserATNSimulator.java:1535)
at org.antlr.v4.runtime.atn.ParserATNSimulator.closure_(ParserATNSimulator.java:1603)
at org.antlr.v4.runtime.atn.ParserATNSimulator.closureCheckingStopState(ParserATNSimulator.java:1535)
at org.antlr.v4.runtime.atn.ParserATNSimulator.closure_(ParserATNSimulator.java:1603)
at org.antlr.v4.runtime.atn.ParserATNSimulator.closureCheckingStopState(ParserATNSimulator.java:1535)
at org.antlr.v4.runtime.atn.ParserATNSimulator.closure_(ParserATNSimulator.java:1603)
at org.antlr.v4.runtime.atn.ParserATNSimulator.closureCheckingStopState(ParserATNSimulator.java:1535)
at org.antlr.v4.runtime.atn.ParserATNSimulator.closure_(ParserATNSimulator.java:1603)
at org.antlr.v4.runtime.atn.ParserATNSimulator.closureCheckingStopState(ParserATNSimulator.java:1535)
at org.antlr.v4.runtime.atn.ParserATNSimulator.closure_(ParserATNSimulator.java:1603)
at org.antlr.v4.runtime.atn.ParserATNSimulator.closureCheckingStopState(ParserATNSimulator.java:1535)
at org.antlr.v4.runtime.atn.ParserATNSimulator.closure_(ParserATNSimulator.java:1603)
at org.antlr.v4.runtime.atn.ParserATNSimulator.closureCheckingStopState(ParserATNSimulator.java:1535)
at org.antlr.v4.runtime.atn.ParserATNSimulator.closure_(ParserATNSimulator.java:1603)
at org.antlr.v4.runtime.atn.ParserATNSimulator.closureCheckingStopState(ParserATNSimulator.java:1535)
at org.antlr.v4.runtime.atn.ParserATNSimulator.closure_(ParserATNSimulator.java:1603)
at org.antlr.v4.runtime.atn.ParserATNSimulator.closureCheckingStopState(ParserATNSimulator.java:1535)
at org.antlr.v4.runtime.atn.ParserATNSimulator.closure_(ParserATNSimulator.java:1603)
at org.antlr.v4.runtime.atn.ParserATNSimulator.closureCheckingStopState(ParserATNSimulator.java:1535)
at org.antlr.v4.runtime.atn.ParserATNSimulator.closure_(ParserATNSimulator.java:1603)
at org.antlr.v4.runtime.atn.ParserATNSimulator.closureCheckingStopState(ParserATNSimulator.java:1535)
at org.antlr.v4.runtime.atn.ParserATNSimulator.closure_(ParserATNSimulator.java:1603)
ANTLR versions is 4.5.1, Java runtime.
Anyone run into this and solved it before please?
Related
I am trying to implement a Django ImageField class function for resizing images however I am not certain where this function accepts my new image dimensions
Running on Linux and Python 3.7
I've had a look at this documentation, but can't quite make sense of it:
https://docs.djangoproject.com/en/1.11/_modules/django/db/models/fields/files/#ImageField
I'd really appreciate it if someone can show me an example of how to use this function.
EDIT
I haven't successfully managed to resize my image dimensions yet, which is what i am trying to achieve. How may I resize this image before I save it given it is being fetched by ImageField (I found the update_dimensions_fields class function for ImageField however i cant figure out how to use it)
class Posts(models.Model):
title = models.CharField(max_length=200, blank=True)
body = models.TextField(blank=True)
created_at = models.DateTimeField(default=datetime.datetime.now)
post_image = models.ImageField(upload_to=get_image_path, blank=True, null=True)
def __str__(self):
return self.title
def save(self, *args, **kwargs):
# I would like to use the function beneath to resize my images before I save them to my database
self.post_image.update_dimension_fields(self, instance, force=False, *args, **kwargs)
super().save(*args, **kwargs) # Call the "real" save() method.
class Meta:
verbose_name_plural = "Posts"
You could use the django-resized library. It resizes images when uploaded and stores them for you.
Usage
from django_resized import ResizedImageField
class Posts(models.Model):
title = models.CharField(max_length=200, blank=True)
body = models.TextField(blank=True)
created_at = models.DateTimeField(default=datetime.datetime.now)
post_image = ResizedImageField(size=[500, 300], upload_to=get_image_path, blank=True, null=True)
def __str__(self):
return self.title
Options
size - max width and height, for example [640, 480]
crop - resize and crop. ['top', 'left'] - top left corner, ['middle', -
'center'] is center cropping, ['bottom', 'right'] - crop right bottom corner.
quality - quality of resized image 1..100
keep_meta - keep EXIF and other meta data, default True
force_format - force the format of the resized image, available formats are the one supported by pillow, default to None
**
This will work
**First of all install "PIL Fork" using 'pip install pillow
from PIL import Image
def __str__(self):
return self.title
def save(self, *args, **kwargs):
super(Posts, self).save(*args, **kwargs)
imag = Image.open(self.post_image.path)
if imag.width > 400 or imag.height> 300:
output_size = (400, 300)
imag.thumbnail(output_size)
imag.save(self.post_image.path)
class Meta:
verbose_name_plural = "Posts"
You can use this method to resize the image before saving it: (you need pip install pillow)
import os
from io import BytesIO
from PIL import Image as PilImage
from django.core.files.base import ContentFile
from django.core.files.uploadedfile import InMemoryUploadedFile, TemporaryUploadedFile
def resize_uploaded_image(image, max_width, max_height):
size = (max_width, max_height)
# Uploaded file is in memory
if isinstance(image, InMemoryUploadedFile):
memory_image = BytesIO(image.read())
pil_image = PilImage.open(memory_image)
img_format = os.path.splitext(image.name)[1][1:].upper()
img_format = 'JPEG' if img_format == 'JPG' else img_format
if pil_image.width > max_width or pil_image.height > max_height:
pil_image.thumbnail(size)
new_image = BytesIO()
pil_image.save(new_image, format=img_format)
new_image = ContentFile(new_image.getvalue())
return InMemoryUploadedFile(new_image, None, image.name, image.content_type, None, None)
# Uploaded file is in disk
elif isinstance(image, TemporaryUploadedFile):
path = image.temporary_file_path()
pil_image = PilImage.open(path)
if pil_image.width > max_width or pil_image.height > max_height:
pil_image.thumbnail(size)
pil_image.save(path)
image.size = os.stat(path).st_size
return image
Then use it in the clean method of the image field in your form:
class ImageForm(forms.Form):
IMAGE_WIDTH = 450
IMAGE_HEIGHT = 450
image = forms.ImageField()
def clean_image(self):
image = self.cleaned_data.get('image')
image = resize_uploaded_image(image, self.IMAGE_WIDTH, self.IMAGE_HEIGHT)
return image
To understand how the resize_uploaded_image method works, you may read about how Django handles uploaded files in the docs, here and here.
You can use the django-imagekit library.
Installation
Install Pillow. (If you're using an ImageField in Django,
you should have already done this.)
pip install django-imagekit
Add 'imagekit' to your INSTALLED_APPS list in your project's settings.py
Models.py
from django.db import models
from imagekit.models import ImageSpecField
from imagekit.processors import ResizeToFill
class Profile(models.Model):
avatar = models.ImageField(upload_to='avatars')
avatar_thumbnail = ImageSpecField(source='avatar',
processors=[ResizeToFill(100, 50)],
format='JPEG',
options={'quality': 60})
Pay attention to the source attribute of ImageSpecField which directs to the actual image field (avatar in this case) as ImageSpecField are virtual in nature, you can read more about it here
Using in your template
<img src="{{ profile.avatar_thumbnail.url }}" />
I'm trying to get the data stream of a sensor transmitter that uses the modbus rtu communication protocol on my raspberry pi 3B. I'm able to get the data with the pymodbus2.5.3 library.
For this I use this code:
from pymodbus.client.sync import ModbusSerialClient # Import the pymodbus library part for syncronous master (=client)
client = ModbusSerialClient(
method='rtu', #Modbus Modus = RTU = via USB & RS485
port='/dev/ttyUSB0', #Connected over ttyUSB0, not AMA0
baudrate=19200, #Baudrate was changed from 38400 to 19200
timeout=3, #
parity='N', #Parity = None
stopbits=2, #Bites was changed from 1 to 2
bytesize=8 #
)
if client.connect(): # Trying to connect to Modbus Server/Slave
#Reading from a holding register
res = client.read_holding_registers(address=100, count=8, unit=1) #Startregister = 100, Registers to be read = 8, Answer size = 1 byte
if not res.isError(): #If Registers don't show Error
print(res.registers) #Print content of registers
else:
print(res) #Print Error Message, for meaning look at (insert git hub)
else: #If not able to connect, do this
print('Cannot connect to the Transmitter M80 SM and Sensor InPro 5000i.')
print('Please check the following things:')
print('Does the RS485-to-USB Adapter have power? Which LEDs are active?')
print('Are the cables connected correctly?')
And get the following output:
[15872, 17996, 16828, 15728, 16283, 45436, 16355, 63231]
With the help of the Modbus Poll and Slave Programms I know that those results should decoded be:
[0.125268, --, 23.53, --, 1.21094, --, 1.77344, --]
To get to the right results I tried the command that the pymodbus github suggests .decode():
res.decode(word_order = little, byte_order = little, formatters = float64)
[I know that those aren't the needed options but I copied the suggested github code to check if it works.]
After putting the code segment into the code the changed part looks like this:
if not res.isError(): #If Registers don't show Error
res.decode(word_order = little, byte_order = little, formatters = float64)
print(res.registers) #Print content of registers
else:
print(res) #Print Error Message, for meaning look at (insert git hub)
When I run this code, I get the following output, that traces to the decoding segment:
NameError: name 'little' is not defined
After this, I imported also the pymodbus part translation. But it showed the same output.
How can I decode my incoming data?
You can use BinaryPayloadDecoder to help decoding your payload, here is a simplified example, change Endian.Big and Endian.Little if needed.
if client.connect(): # Trying to connect to Modbus Server/Slave
#Reading from a holding register
res = client.read_holding_registers(address=100, count=8, unit=1) #Startregister = 100, Registers to be read = 8, Answer size = 1 byte
# ====== added code start ======
decoder = BinaryPayloadDecoder.fromRegisters(res.registers, Endian.Little, wordorder=Endian.Little)
first_reading = decoder.decode_32bit_float()
second_reading = decoder.decode_32bit_float()
# ====== added code end ======
if not res.isError(): #If Registers don't show Error
print(res.registers) #Print content of registers
else:
print(res) #Print Error Message, for meaning look at (insert git hub)
Remember to import from pymodbus.payload import BinaryPayloadDecoder at top and add necessary exception handlers in your final code.
Reference document: https://pymodbus.readthedocs.io/en/latest/source/library/pymodbus.html#pymodbus.payload.BinaryPayloadDecoder
How to re-create an equivalent to following Linux bash statement in Deno?
docker compose exec container_name -uroot -ppass db_name < ./dbDump.sql
I have tried the following:
const encoder = new TextEncoder
const p = await Deno.run({
cmd: [
'docker',
'compose',
'exec',
'container_name',
'mysql',
'-uroot',
'-ppass',
'db_name',
],
stdout: 'piped',
stderr: 'piped',
stdin: "piped",
})
await p.stdin.write(encoder.encode(await Deno.readTextFile('./dbDump.sql')))
await p.stdin.close()
await p.close()
But for some reason whenever I do it this way I get an error ERROR 1064 (42000) at line 145: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version which does not happen when I perform the exact same command in the bash.
Could someone please explain me how it has to be done properly?
Without a sample input file, it's impossible to be certain of your exact issue.
Given the context though, I suspect that your input file is too large for a single proc.stdin.write() call. Try using the writeAll() function to make sure the full payload goes through:
import { writeAll } from "https://deno.land/std#0.119.0/streams/conversion.ts";
await writeAll(proc.stdin, await Deno.readFile(sqlFilePath));
To show what this fixes, here's a Deno program pipe-to-wc.ts which passes its input to the Linux 'word count' utility (in character-counting mode):
#!/usr/bin/env -S deno run --allow-read=/dev/stdin --allow-run=wc
const proc = await Deno.run({
cmd: ['wc', '-c'],
stdin: 'piped',
});
await proc.stdin.write(await Deno.readFile('/dev/stdin'));
proc.stdin.close();
await proc.status();
If we use this program with a small input, the count lines up:
# use the shebang to make the following commands easier
$ chmod +x pipe-to-wc.ts
$ dd if=/dev/zero bs=1024 count=1 | ./pipe-to-wc.ts
1+0 records in
1+0 records out
1024 bytes (1.0 kB, 1.0 KiB) copied, 0.000116906 s, 8.8 MB/s
1024
But as soon as the input is big, only 65k bytes are going through!
$ dd if=/dev/zero bs=1024 count=100 | ./pipe-to-wc.ts
100+0 records in
100+0 records out
102400 bytes (102 kB, 100 KiB) copied, 0.0424347 s, 2.4 MB/s
65536
To fix this issue, let's replace the write() call with writeAll():
#!/usr/bin/env -S deno run --allow-read=/dev/stdin --allow-run=wc
const proc = await Deno.run({
cmd: ['wc', '-c'],
stdin: 'piped',
});
import { writeAll } from "https://deno.land/std#0.119.0/streams/conversion.ts";
await writeAll(proc.stdin, await Deno.readFile('/dev/stdin'));
proc.stdin.close();
await proc.status();
Now all the bytes are getting passed through on big inputs :D
$ dd if=/dev/zero bs=1024 count=1000 | ./pipe-to-wc.ts
1000+0 records in
1000+0 records out
1024000 bytes (1.0 MB, 1000 KiB) copied, 0.0854184 s, 12.0 MB/s
1024000
Note that this will still fail on huge inputs once they exceed the amount of memory available to your program. The writeAll() solution should be fine up to 100 megabytes or so. After that point you'd probably want to switch to a streaming solution.
First, a couple of notes:
Deno currently doesn't offer a way to create a detached subprocess. (You didn't mention this, but it seems potentially relevant to your scenario given typical docker compose usage) See denoland/deno#5501.
Deno's subprocess API is currently being reworked. See denoland/deno#11016.
Second, here are links to the relevant docs:
docker-compose exec
CLI APIs > Deno.run
Manual > Creating a subprocess (Deno v1.17.0)
Now, here's a commented breakdown of how to create a subprocess (according to the current API) using your scenario as an example:
module.ts:
const dbUser = 'actual_database_username';
const dbPass = 'actual_database_password'
const dbName = 'actual_database_name';
const dockerExecProcCmd = ['mysql', '-u', dbUser, '-p', dbPass, dbName];
const serviceName = 'actual_compose_service_name';
// Build the run command
const cmd = ['docker', 'compose', 'exec', '-T', serviceName, ...dockerExecProcCmd];
/**
* Create the subprocess
*
* For now, leave `stderr` and `stdout` undefined so they'll print
* to your console while you are debugging. Later, you can pipe (capture) them
* and handle them in your program
*/
const p = Deno.run({
cmd,
stdin: 'piped',
// stderr: 'piped',
// stdout: 'piped',
});
/**
* If you use a relative path, this will be relative to `Deno.cwd`
* at the time the subprocess is created
*
* https://doc.deno.land/deno/stable/~/Deno.cwd
*/
const sqlFilePath = './dbDump.sql';
// Write contents of SQL script to stdin
await p.stdin.write(await Deno.readFile(sqlFilePath));
/**
* Close stdin
*
* I don't know how `mysql` handles `stdin`, but if it needs the EOT sent by
* closing and you don't need to write to `stdin` any more, then this is correct
*/
p.stdin.close();
// Wait for the process to finish (either OK or NOK)
const {code} = await p.status();
console.log({'docker-compose exit status code': code});
// Not strictly necessary, but better to be explicit
p.close();
I am trying out a Python application to connect to a Janusgraph 0.2.0. I followed all the setup instructions and I am able to create elements in the graph and traverse them successfully.
import asyncio
from goblin import Goblin
from quart import jsonify, Quart, serving
from app.models import Person, Knows
loop = asyncio.get_event_loop()
goblin_app = loop.run_until_complete(Goblin.open(loop,
hosts = ['localhost'],
port = '8182',
scheme = 'ws'))
goblin_app.register(Person, Knows)
print("Initialized all the goblin stuff")
quart_app = Quart(name)
async def create(app, data):
session = await app.session()
session.add(data)
await session.flush()
return data
leif = Person()
leif.name = 'Leif'
leif.age = 28
leif = loop.run_until_complete(create(goblin_app, leif))
jon = Person()
jon.name = 'Jon'
jon.age = 32
jon = loop.run_until_complete(create(goblin_app, jon))
works_with = Knows(leif, jon)
works_with = loop.run_until_complete(goblin_app, works_with)
However, when I try to connect from my application and send session.flush() to create an element, the application freezes and nothing else happens.
In the gremlin-server.log I am seeing the following error:
1109015 [gremlin-server-worker-1] WARN
org.apache.tinkerpop.gremlin.server.handler.WsGremlinBinaryRequestDecoder
- Gremlin Server is not configured with a serializer for the requested mime type [application/vnd.gremlin-v3.0+json] - using
org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV1d0
by default 1109035 [gremlin-server-worker-1] WARN
org.apache.tinkerpop.gremlin.driver.ser.AbstractGraphSONMessageSerializerV1d0
- Request [PooledUnsafeDirectByteBuf(ridx: 558, widx: 558, cap: 592)] could not be deserialized by
org.apache.tinkerpop.gremlin.driver.ser.AbstractGraphSONMessageSerializerV1d0.
1109039 [gremlin-server-worker-1] WARN
org.apache.tinkerpop.gremlin.server.handler.OpSelectorHandler -
Invalid OpProcessor requested [null]
org.apache.tinkerpop.gremlin.server.op.OpProcessorException: Invalid
OpProcessor requested [null] at
org.apache.tinkerpop.gremlin.server.handler.OpSelectorHandler.decode(OpSelectorHandler.java:95)
at
org.apache.tinkerpop.gremlin.server.handler.OpSelectorHandler.decode(OpSelectorHandler.java:50)
at
io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:88)
at
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356)
at
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342)
at
io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:335)
at
io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:102)
at
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356)
at
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342)
at
io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:335)
at
io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:102)
at
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356)
at
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342)
at
io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:335)
at
io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:102)
at
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356)
at
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342)
at
io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:335)
at
io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:102)
at
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356)
at
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342)
at
io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:335)
at
io.netty.handler.codec.http.websocketx.WebSocketServerProtocolHandler$1.channelRead(WebSocketServerProtocolHandler.java:159)
at
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356)
at
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342)
at
io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:335)
at
io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:312)
at
io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:286)
at
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356)
at
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342)
at
io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:335)
at
io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1302)
at
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356)
at
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342)
at
io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
at
io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:131)
at
io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:646)
at
io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:581)
at
io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:498)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:460) at
io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:131)
at java.lang.Thread.run(Thread.java:745) ~
I found some information about replacing the version the GraphSON versions in the gremlin-server.yaml file to add the missing serializer for gremlin-v3.0+json, and I did that, however when I added that I get an error about not being able to find the configured serializer class:
10348 [main] WARN org.apache.tinkerpop.gremlin.server.AbstractChannelizer - Could not find configured serializer class - org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV3d0 - it will not be available 1
So my questions are:
Is there a way that I can change the version of the serializer that my application is sending to the Gremlin Server to one of the compatible versions
Would it work if I download the GraphSON version 3.0 and place it in the server? This would mean that I would have to upgrade the version of Gremlin Server packaged with Janusgraph, which seems to be too much...
Has anyone run into a similar problem and has any suggestions ?
Check and make sure the gremlinpython version is aligned with the Apache TinkerPop version 3.2.6 that JanusGraph 0.2.0 uses.
I am rather new to Qt, maybe that's why I cant fully understand the child-parent concept. I need to perform some sql query. I set the QSqlQuery, perform the "prepare and bind" operation and exec it. Next I pass it to the model and display the data. The problem occurs when closing the window - I get a memory violation error. The error occurs only, when I create the model with a parent. Here's the code:
QSqlQuery query;
query.prepare(QString("SELECT \
%1 as nazwa \
, kontrahentid \
FROM kontrahent WHERE %2 ilike ?"
).arg(showWhat, searchBy) //handled above, no need to escape
);
query.addBindValue(searchString); //user input data - so bind it
if (!query.exec()) {
qDebug() << query.lastError();
QApplication::restoreOverrideCursor();
return;
}
if (model == NULL)
// model = new QSqlQueryModel; // app closes the window correctly
model = new QSqlQueryModel(this); // app crashes when closing the window
model->setQuery(query);
if (model->lastError().isValid()) {
qDebug() << model->lastError();
QApplication::restoreOverrideCursor();
return;
}
model->setHeaderData(0, Qt::Horizontal, "ID");
ui.kontrahenciList->setModel(model);
//ui.kontrahenciList->setModelColumn(1);
ui.kontrahenciList->show();
Here's the error I'm getting:
Unhandled exception at 0x0fe29f9a (qsqlpsqld.dll) in HurBudClientGUI.exe: 0xC0000005: Access violation reading location 0x00000004.
and the call stack:
qsqlpsqld.dll!QScopedPointer<QObjectData,QScopedPointerDeleter<QObjectData> >::data() Line 143 + 0x3 bytes C++
qsqlpsqld.dll!qGetPtrHelper<QScopedPointer<QObjectData,QScopedPointerDeleter<QObjectData> > >(const QScopedPointer<QObjectData,QScopedPointerDeleter<QObjectData> > & p) Line 919 + 0xb bytes C++
qsqlpsqld.dll!QPSQLDriver::d_func() Line 106 + 0x13 bytes C++
qsqlpsqld.dll!QPSQLResultPrivate::privDriver() Line 212 C++
qsqlpsqld.dll!QPSQLResultPrivate::deallocatePreparedStmt() Line 306 + 0xc bytes C++
qsqlpsqld.dll!QPSQLResult::~QPSQLResult() Line 328 C++
qsqlpsqld.dll!QPSQLResult::`scalar deleting destructor'() + 0xf bytes C++
Qt5Sqld.dll!QSqlQueryPrivate::~QSqlQueryPrivate() Line 94 + 0x23 bytes C++
Qt5Sqld.dll!QSqlQueryPrivate::`scalar deleting destructor'() + 0xf bytes C++
Qt5Sqld.dll!QSqlQuery::~QSqlQuery() Line 245 + 0x1e bytes C++
Qt5Sqld.dll!QSqlQueryModelPrivate::~QSqlQueryModelPrivate() Line 90 + 0x3d bytes C++
Qt5Sqld.dll!QSqlQueryModelPrivate::`scalar deleting destructor'() + 0xf bytes C++
Qt5Cored.dll!672cbf06()
[Frames below may be incorrect and/or missing, no symbols loaded for Qt5Cored.dll]
Qt5Cored.dll!672cb92a()
Qt5Cored.dll!672c03f4()
Qt5Cored.dll!67200dc4()
Qt5Cored.dll!67203608()
Qt5Sqld.dll!QSqlQueryModel::~QSqlQueryModel() Line 175 + 0x9 bytes C++
As I mentioned above: the error doesn't happen when (one of below):
I create QSqlQueryModel without the parent (model = new QSqlQueryModel;)
I pass "static" query to QSqlQueryModel (regardless of having the parent).
eg:
model->setQuery(
QSqlQuery(
QString("SELECT \
%1 as nazwa \
, kontrahentid \
FROM kontrahent"
).arg(showWhat)
)
);
What am I doing wrong?
And the real question is: what is the purpose for QSqlQueryModel having a parent? If I delete it manually in the window's destructor - is there any diffrence?
I guess this is a bug - I reported it on qt bugtracker:
https://bugreports.qt.io/browse/QTBUG-43889
This is the key part:
if (model == NULL)
// model = new QSqlQueryModel; // app closes the window correctly
model = new QSqlQueryModel(this); // app crashes when closing the window
The parent-child concept in Qt provides many features, with automatic child destruction being one of them.
If any QObject has other QObject set as a parent, then when parent QObject is deleted, the child object will also be deleted.
Now, you mentioned you do explicitly delete the model in destructor of the window. You should not. If you define this as a parent, then the model will be automatically deleted together with this, but it was already deleted by you in the destructor, so model is deleted twice, thus your error appears.
So I removed the "delete operation" code in the destructor. Error still occurs, the only difference is diffrent call stack.
error message:
Unhandled exception at 0x0f249f9a (qsqlpsqld.dll) in HurBudClientGUI.exe: 0xC0000005: Access violation reading location 0x00000004.
call stack:
qsqlpsqld.dll!QScopedPointer<QObjectData,QScopedPointerDeleter<QObjectData> >::data() Line 143 + 0x3 bytes C++
qsqlpsqld.dll!qGetPtrHelper<QScopedPointer<QObjectData,QScopedPointerDeleter<QObjectData> > >(const QScopedPointer<QObjectData,QScopedPointerDeleter<QObjectData> > & p) Line 919 + 0xb bytes C++
qsqlpsqld.dll!QPSQLDriver::d_func() Line 106 + 0x13 bytes C++
qsqlpsqld.dll!QPSQLResultPrivate::privDriver() Line 212 C++
qsqlpsqld.dll!QPSQLResultPrivate::deallocatePreparedStmt() Line 306 + 0xc bytes C++
qsqlpsqld.dll!QPSQLResult::~QPSQLResult() Line 328 C++
qsqlpsqld.dll!QPSQLResult::`scalar deleting destructor'() + 0xf bytes C++
Qt5Sqld.dll!QSqlQueryPrivate::~QSqlQueryPrivate() Line 94 + 0x23 bytes C++
Qt5Sqld.dll!QSqlQueryPrivate::`scalar deleting destructor'() + 0xf bytes C++
Qt5Sqld.dll!QSqlQuery::~QSqlQuery() Line 245 + 0x1e bytes C++
Qt5Sqld.dll!QSqlQueryModelPrivate::~QSqlQueryModelPrivate() Line 90 + 0x3d bytes C++
Qt5Sqld.dll!QSqlQueryModelPrivate::`scalar deleting destructor'() + 0xf bytes C++
Qt5Cored.dll!QScopedPointerDeleter<QObjectData>::cleanup(QObjectData * pointer) Line 62 + 0x20 bytes C++
Qt5Cored.dll!QScopedPointer<QObjectData,QScopedPointerDeleter<QObjectData> >::~QScopedPointer<QObjectData,QScopedPointerDeleter<QObjectData> >() Line 109 + 0x9 bytes C++
Qt5Cored.dll!QObject::~QObject() Line 940 + 0x15 bytes C++
Qt5Cored.dll!QAbstractItemModel::~QAbstractItemModel() Line 1454 + 0xf bytes C++
Qt5Cored.dll!QAbstractTableModel::~QAbstractTableModel() Line 3299 + 0x8 bytes C++
Qt5Sqld.dll!QSqlQueryModel::~QSqlQueryModel() Line 175 + 0x9 bytes C++
HurBudClientGUI.exe!QSqlQueryModel::`scalar deleting destructor'() + 0x10 bytes C++
Qt5Cored.dll!QObjectPrivate::deleteChildren() Line 1841 + 0x24 bytes C++
Qt5Widgetsd.dll!QWidget::~QWidget() Line 1488 C++
Qt5Widgetsd.dll!QDockWidget::~QDockWidget() Line 1172 + 0x22 bytes C++
HurBudClientGUI.exe!searchDock::~searchDock() Line 28 + 0x1c bytes C++
searchDock is the class I'm working with.
I guess I solved it. When the model is initialized as view's child:
model = new QSqlQueryModel(this);
The problem is order of operations. When I close the connection and remove the database in the destructor of my class - the database gets disconnected and no further operations are possible. But after my class' destructor, destructors of its base classes get into action - one by another, as ordered by inheritance. When QObject::~QObject() is executed, it gets to the
QObjectPrivate::deleteChildren()
method. And then, it finally gets to delete the model. The model wants to free the resources - which means QSqlResult (QPSQLResult to be specific in that case). This it how it looks:
QPSQLResult::~QPSQLResult()
{
Q_D(QPSQLResult);
cleanup();
if (d->preparedQueriesEnabled && !d->preparedStmtId.isNull())
d->deallocatePreparedStmt();
};
So here Qt tries to deallocate preparedStatement - regardless of the fact, that the connection no longer exists:
void QPSQLResultPrivate::deallocatePreparedStmt()
{
const QString stmt = QLatin1String("DEALLOCATE ") + preparedStmtId;
PGresult *result = privDriver()->exec(stmt);
if (PQresultStatus(result) != PGRES_COMMAND_OK)
qWarning("Unable to free statement: %s", PQerrorMessage(privDriver()->connection));
PQclear(result);
preparedStmtId.clear();
};
So - to make it work properly, I wolud have to call
QSqlQueryModel::~QSqlQueryModel()
or
QSqlQueryModel::clear()
BEFORE closing the connection with the DB. I still think it's a bug.