dataflow

TPL Dataflow: design for parallelism while keeping order

亡梦爱人 提交于 2019-12-04 10:00:36
I have never worked with TPL before so I was wondering whether this can be done with it: My application creates a gif image animation file from a lot of frames. I start with a list of Bitmap which represents the frames of the gif file and need to do the following for each frame: paint a number of text/bitmaps onto the frame crop the frame resize the frame reduce the image to 256 colors Obviously this process can be done in parallel for all the frames in the list but for each frame the order of steps needs to be the same. After that, I need to write all the frames to the gif file. Therefore all

Confusion between Behavioural and Dataflow model Programs in VHDL

混江龙づ霸主 提交于 2019-12-04 09:21:56
I'm using the textbook "VHDL: Programming By Example" by Douglas L Perry, Fourth Edition. He gave an example of the Dataflow programming model in page 4: Code I: ENTITY mux IS PORT ( a, b, c, d : IN BIT; s0, s1 : IN BIT; x, : OUT BIT); END mux; ARCHITECTURE dataflow OF mux IS SIGNAL select : INTEGER; BEGIN select <= 0 WHEN s0 = ‘0’ AND s1 = ‘0’ ELSE 1 WHEN s0 = ‘1’ AND s1 = ‘0’ ELSE 2 WHEN s0 = ‘0’ AND s1 = ‘1’ ELSE 3; x <= a AFTER 0.5 NS WHEN select = 0 ELSE b AFTER 0.5 NS WHEN select = 1 ELSE c AFTER 0.5 NS WHEN select = 2 ELSE d AFTER 0.5 NS; END dataflow; Now in page 17, Code II LIBRARY

Share state among operators in Flink

自闭症网瘾萝莉.ら 提交于 2019-12-03 21:20:07
问题 I wonder if it is possible in Flink to share the state among operators. Say, for instance, that I have partitioning by key on an operator and I need a piece of state of partition A inside partition C (for any reason) (fig 1.a), or I need the state of operator C in downstream operator F (fig 1.b). I know it is possible to broadcast records to all partitions. So, if you include the internal state of an operator inside the records, you can share your internal state with downstream operators.

What is the difference between Dataflow programming and Reactive programming?

核能气质少年 提交于 2019-12-03 09:27:09
问题 I really can't see the difference between them. They are both about data flowing through instructions and the propagation of changes in the input data. I've read this book (authored by Matt Carcki) and it clearly says that the are both the same. On the other hand the wikipedia establish Reactive programming as a form of Dataflow programming and this stackoverflow answer does it too. So, what is the conceptual difference between Reactive programming and Dataflow programming? 回答1: Reactive

TPL Dataflow vs plain Semaphore

强颜欢笑 提交于 2019-12-03 08:53:10
I have a requirement to make a scalable process. The process has mainly I/O operations with some minor CPU operations (mainly deserializing strings). The process query the database for a list of urls, then fetches data from these urls, deserilize the downloaded data to objects, then persist some of the data into crm dynamics and also to another database. Afterwards I need to update the first database which urls were processed. Part of the requirement is to make the parallelism degree configurable. Initially I thought to implement it via a sequence of tasks with await and limit the parallelism

How to create groups of N elements from a PCollection Apache Beam Python

我们两清 提交于 2019-12-03 08:31:22
I am trying to accomplish something like this: Batch PCollection in Beam/Dataflow The answer in the above link is in Java, whereas the language I'm working with is Python. Thus, I require some help getting a similar construction. Specifically I have this: p = beam.Pipeline (options = pipeline_options) lines = p | 'File reading' >> ReadFromText (known_args.input) After this, I need to create another PCollection but with a List of N rows of "lines" since my use case requires a group of rows. I can not operate line by line. I tried a ParDo Function using variables for count associating with the

Dataflow Programming API for Java? [closed]

廉价感情. 提交于 2019-12-03 06:55:58
As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance. I am looking for a Dataflow / Concurrent Programming API for Java. I know there's DataRush , but it's not free. What I'm interested in specifically is multicore data processing, and not distributed, which rules out MapReduce or Hadoop . Any thoughts? Thanks,

Is there an alternative to IntrabundleParallelization in Dataflow 2.1.0?

痴心易碎 提交于 2019-12-02 17:04:07
问题 According to release notes of dataflow 2.X, IntraBundleParallelization is removed. Is there a way to control/increase parallelism of DoFns on dataflow 2.1.0 ? I was getting better performance when I used IntrabundleParallelization on 1.9.0 version of dataflow. 回答1: It was removed because its implementation keeps a handle on the ProcessContext of a ProcessElement call after the call completes, and this is unsafe and not guaranteed to work. However, I agree that it was a useful abstraction, and

Is there an alternative to IntrabundleParallelization in Dataflow 2.1.0?

筅森魡賤 提交于 2019-12-02 09:31:07
According to release notes of dataflow 2.X, IntraBundleParallelization is removed. Is there a way to control/increase parallelism of DoFns on dataflow 2.1.0 ? I was getting better performance when I used IntrabundleParallelization on 1.9.0 version of dataflow. It was removed because its implementation keeps a handle on the ProcessContext of a ProcessElement call after the call completes, and this is unsafe and not guaranteed to work. However, I agree that it was a useful abstraction, and it is unfortunate that we don't have a replacement yet. As a workaround, you can try the following: In your

verilog number of ones in array

末鹿安然 提交于 2019-12-02 05:15:19
问题 I am trying to know the number of ones in a 4-bit binary number in verilog but no output happens. I've tried several approaches this is the one I think should work but it doesn't. module ones(one,in); input [3:0]in; output [1:0]one; assign one = 2'b00; assign one = one+in[3]+in[2]+in[1]+in[0] ; endmodule 回答1: First, you can't assign the variable twice. Second, your range is off, 2 bits can only go from 0 to 3. You need a 3 bit output to count up to 4. This is more like what you need: module