Leaf | Distributed ID Generate Service

 by   Meituan-Dianping Java Version: Current License: Apache-2.0

kandi X-RAY | Leaf Summary

kandi X-RAY | Leaf Summary

Leaf is a Java library. Leaf has no bugs, it has no vulnerabilities, it has build file available, it has a Permissive License and it has medium support. You can download it from GitHub.

Leaf refers to some common ID generation schemes in the industry, including redis, UUID, snowflake, etc. Each of the above approaches has its own problems, so we decided to implement a set of distributed ID generation services to meet the requirements. At present, Leaf covers Meituan review company's internal finance, catering, takeaway, hotel travel, cat's eye movie and many other business lines. On the basis of 4C8G VM, through the company RPC method, QPS pressure test results are nearly 5w/s, TP999 1ms. You can use it to encapsulate a distributed unique id distribution center in a service-oriented SOA architecture as the id distribution provider for all applications.
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            kandi-support Support

              Leaf has a medium active ecosystem.
              It has 5940 star(s) with 1742 fork(s). There are 167 watchers for this library.
              OutlinedDot
              It had no major release in the last 6 months.
              There are 53 open issues and 90 have been closed. On average issues are closed in 45 days. There are 36 open pull requests and 0 closed requests.
              It has a neutral sentiment in the developer community.
              The latest version of Leaf is current.

            kandi-Quality Quality

              Leaf has 0 bugs and 0 code smells.

            kandi-Security Security

              Leaf has no vulnerabilities reported, and its dependent libraries have no vulnerabilities reported.
              Leaf code analysis shows 0 unresolved vulnerabilities.
              There are 0 security hotspots that need review.

            kandi-License License

              Leaf is licensed under the Apache-2.0 License. This license is Permissive.
              Permissive licenses have the least restrictions, and you can use them in most projects.

            kandi-Reuse Reuse

              Leaf releases are not available. You will need to build from source code and install.
              Build file is available. You can build the component from source.
              Installation instructions are not available. Examples and code snippets are available.
              Leaf saves you 825 person hours of effort in developing the same functionality from scratch.
              It has 1892 lines of code, 162 functions and 38 files.
              It has medium code complexity. Code complexity directly impacts maintainability of the code.

            Top functions reviewed by kandi - BETA

            kandi has reviewed Leaf and discovered the below as its top functions. This is intended to give you an instant insight into Leaf implemented functionality, and help decide if they suit your requirements.
            • Initialize node
            • Update local worker id
            • Build json string
            • Schedules a scheduled upload data
            • Get ID from cache
            • Wait for the thread to run
            • Update segment from db
            • Get the next segment id from the buffer
            • Get IP address
            • Get host address
            • Gets the IP address
            • Get host address
            • Initialize cache
            • Update cache from db
            • Update cache from every minute
            • Returns a string representation of this buffer
            • Get the cache of segments
            • Update the maxId allocation for a given tag
            • Update maxId allocations for a custom path
            • Gets the db information
            • Returns a string representation of the parameters
            • Decode a SnowflakeId string
            • Get the next item
            Get all kandi verified functions for this library.

            Leaf Key Features

            No Key Features are available at this moment for Leaf.

            Leaf Examples and Code Snippets

            copy iconCopy
            const HSLToRGB = (h, s, l) => {
              s /= 100;
              l /= 100;
              const k = n => (n + h / 30) % 12;
              const a = s * Math.min(l, 1 - l);
              const f = n =>
                l - a * Math.max(-1, Math.min(k(n) - 3, Math.min(9 - k(n), 1)));
              return [255 * f(0), 255 *  
            copy iconCopy
            from datetime import timedelta, date
            
            def daterange(start, end):
              return [start + timedelta(n) for n in range(int((end - start).days))]
            
            
            from datetime import date
            
            daterange(date(2020, 10, 1), date(2020, 10, 5))
            # [date(2020, 10, 1), date(2020, 10,  
            Returns the leaf at v .
            pythondot img3Lines of Code : 35dot img3License : Permissive (MIT License)
            copy iconCopy
            def get_leaf(self, v):
                    """
                    Tree structure and array storage:
                    Tree index:
                         0         -> storing priority sum
                        / \
                      1     2
                     / \   / \
                    3   4 5   6    -> storing priority for   
            Recursively prints a subtree to a leaf path .
            javadot img4Lines of Code : 20dot img4License : Non-SPDX (GNU General Public License v3.0)
            copy iconCopy
            public void rootToLeafPaths(BinaryNode node, E[] pathList, int pathLength) {
                    if (node == null) return;
            
                    pathList[pathLength] = node.value;
                    pathLength++;
            
                    // if its a leaf node then print the list
                    if (node.left   
            Return a list of leaf level keys from a CrossedColumn .
            pythondot img5Lines of Code : 16dot img5License : Non-SPDX (Apache License 2.0)
            copy iconCopy
            def _collect_leaf_level_keys(cross):
              """Collects base keys by expanding all nested crosses.
            
              Args:
                cross: A `CrossedColumn`.
            
              Returns:
                A list of strings or `CategoricalColumn` instances.
              """
              leaf_level_keys = []
              for k in cross.key  

            Community Discussions

            QUESTION

            Why does gcc -march=znver1 restrict uint64_t vectorization?
            Asked 2022-Apr-10 at 02:47

            I'm trying to make sure gcc vectorizes my loops. It turns out, that by using -march=znver1 (or -march=native) gcc skips some loops even though they can be vectorized. Why does this happen?

            In this code, the second loop, which multiplies each element by a scalar is not vectorised:

            ...

            ANSWER

            Answered 2022-Apr-10 at 02:47

            The default -mtune=generic has -mprefer-vector-width=256, and -mavx2 doesn't change that.

            znver1 implies -mprefer-vector-width=128, because that's all the native width of the HW. An instruction using 32-byte YMM vectors decodes to at least 2 uops, more if it's a lane-crossing shuffle. For simple vertical SIMD like this, 32-byte vectors would be ok; the pipeline handles 2-uop instructions efficiently. (And I think is 6 uops wide but only 5 instructions wide, so max front-end throughput isn't available using only 1-uop instructions). But when vectorization would require shuffling, e.g. with arrays of different element widths, GCC code-gen can get messier with 256-bit or wider.

            And vmovdqa ymm0, ymm1 mov-elimination only works on the low 128-bit half on Zen1. Also, normally using 256-bit vectors would imply one should use vzeroupper afterwards, to avoid performance problems on other CPUs (but not Zen1).

            I don't know how Zen1 handles misaligned 32-byte loads/stores where each 16-byte half is aligned but in separate cache lines. If that performs well, GCC might want to consider increasing the znver1 -mprefer-vector-width to 256. But wider vectors means more cleanup code if the size isn't known to be a multiple of the vector width.

            Ideally GCC would be able to detect easy cases like this and use 256-bit vectors there. (Pure vertical, no mixing of element widths, constant size that's am multiple of 32 bytes.) At least on CPUs where that's fine: znver1, but not bdver2 for example where 256-bit stores are always slow due to a CPU design bug.

            You can see the result of this choice in the way it vectorizes your first loop, the memset-like loop, with a vmovdqu [rdx], xmm0. https://godbolt.org/z/E5Tq7Gfzc

            So given that GCC has decided to only use 128-bit vectors, which can only hold two uint64_t elements, it (rightly or wrongly) decides it wouldn't be worth using vpsllq / vpaddd to implement qword *5 as (v<<2) + v, vs. doing it with integer in one LEA instruction.

            Almost certainly wrongly in this case, since it still requires a separate load and store for every element or pair of elements. (And loop overhead since GCC's default is not to unroll except with PGO, -fprofile-use. SIMD is like loop unrolling, especially on a CPU that handles 256-bit vectors as 2 separate uops.)

            I'm not sure exactly what GCC means by "not vectorized: unsupported data-type". x86 doesn't have a SIMD uint64_t multiply instruction until AVX-512, so perhaps GCC assigns it a cost based on the general case of having to emulate it with multiple 32x32 => 64-bit pmuludq instructions and a bunch of shuffles. And it's only after it gets over that hump that it realizes that it's actually quite cheap for a constant like 5 with only 2 set bits?

            That would explain GCC's decision-making process here, but I'm not sure it's exactly the right explanation. Still, these kinds of factors are what happen in a complex piece of machinery like a compiler. A skilled human can easily make smarter choices, but compilers just do sequences of optimization passes that don't always consider the big picture and all the details at the same time.

            -mprefer-vector-width=256 doesn't help: Not vectorizing uint64_t *= 5 seems to be a GCC9 regression

            (The benchmarks in the question confirm that an actual Zen1 CPU gets a nearly 2x speedup, as expected from doing 2x uint64 in 6 uops vs. 1x in 5 uops with scalar. Or 4x uint64_t in 10 uops with 256-bit vectors, including two 128-bit stores which will be the throughput bottleneck along with the front-end.)

            Even with -march=znver1 -O3 -mprefer-vector-width=256, we don't get the *= 5 loop vectorized with GCC9, 10, or 11, or current trunk. As you say, we do with -march=znver2. https://godbolt.org/z/dMTh7Wxcq

            We do get vectorization with those options for uint32_t (even leaving the vector width at 128-bit). Scalar would cost 4 operations per vector uop (not instruction), regardless of 128 or 256-bit vectorization on Zen1, so this doesn't tell us whether *= is what makes the cost-model decide not to vectorize, or just the 2 vs. 4 elements per 128-bit internal uop.

            With uint64_t, changing to arr[i] += arr[i]<<2; still doesn't vectorize, but arr[i] <<= 1; does. (https://godbolt.org/z/6PMn93Y5G). Even arr[i] <<= 2; and arr[i] += 123 in the same loop vectorize, to the same instructions that GCC thinks aren't worth it for vectorizing *= 5, just different operands, constant instead of the original vector again. (Scalar could still use one LEA). So clearly the cost-model isn't looking as far as final x86 asm machine instructions, but I don't know why arr[i] += arr[i] would be considered more expensive than arr[i] <<= 1; which is exactly the same thing.

            GCC8 does vectorize your loop, even with 128-bit vector width: https://godbolt.org/z/5o6qjc7f6

            Source https://stackoverflow.com/questions/71811588

            QUESTION

            System.IO.FileInfo and Relative Paths
            Asked 2022-Mar-30 at 22:32

            I was wondering if someone could help me understand why does System.IO.FileInfo behaves differently on Windows than on Linux when handling relative paths.

            Example
            • On Linux
            ...

            ANSWER

            Answered 2021-Dec-07 at 15:50

            Feels a bit duplicate, but since you asked..

            I'm sorry I don't know about Linux, but in Windows:

            You can add a test first to see if the path is relative and if so, convert it to absolute like:

            Source https://stackoverflow.com/questions/70254096

            QUESTION

            Dictionary leaf generator
            Asked 2022-Mar-30 at 08:42

            Here it is my tree, a nested dictionary

            ...

            ANSWER

            Answered 2021-Dec-13 at 16:38

            You are not using the result of the recursive call. That worked for print_leaves which didn't have a return value, but that doesn't work for a function with return or yield.

            Here is the long version:

            Source https://stackoverflow.com/questions/70337670

            QUESTION

            Resolve object recursively with type safe property access in two steps
            Asked 2022-Mar-21 at 15:33

            I'm trying to replace the string types in the following function with more specific types that ensure type safe property access:

            ...

            ANSWER

            Answered 2022-Mar-21 at 14:18

            I can't believe this abomination actually works:

            Source https://stackoverflow.com/questions/71529277

            QUESTION

            Count the occurrences of a group of words in a text column in SQL
            Asked 2022-Feb-28 at 19:22

            I have two tables as follows :

            ...

            ANSWER

            Answered 2022-Feb-26 at 05:47

            Create Split Function like this

            Source https://stackoverflow.com/questions/71274186

            QUESTION

            How to deal with complex list and dictionary on python
            Asked 2022-Feb-08 at 00:52

            I've been working on python to make a program which need to handle complex problem from list of dict. The thing is I need to transform this data into dictionary and sort it. The input for this function is come from trees. The code I share here is working, but takes a long time to run. In here I wanna ask is there any idea to make this function run more faster in python? I use python 3.7.3 if you ask. The reason I wanna improve this code is because when I tried to make input data for this function need around 3-4 hours, but to run this function need time around 21-22 hours (this really shock me).

            here is the structure of data that I input on below:

            ...

            ANSWER

            Answered 2022-Feb-08 at 00:52

            Without having the full code to test outputs this is harder to do, but it seems that there are some redundant processes that you are adding elements to a list of lists only to flatten that list and add that to a dictionary as a set. You can increase some of the speed and memory by removing that and instead just adding it to the dictionary right away.

            There are some other tweaks that can be done such as using f-strings instead of string concatenation, using list comprehension, and removing having to do the same math in the loop (time_range * gamma) and instead just reference it by memory.

            But these are all minor tweaks compared to your step one process which looks to be the largest time sink (approx N^4 in time complexity). I am unsure if it is larger as I don't see the functions that you use inside that for loop, but tweaking that to reduce the number of calculations would provide the largest benefit to time savings.

            Source https://stackoverflow.com/questions/70180233

            QUESTION

            JavaScript user input variable
            Asked 2022-Feb-04 at 16:30

            n00b here!

            I have managed to assemble JavaScript code and I don't understand why is not working correct.

            The code is designed to calculate the difference between a given date and today's date. I guess my logic in the script is not correct as no error show in the console.

            Here is the code:

            ...

            ANSWER

            Answered 2022-Feb-03 at 23:26

            QUESTION

            Path to each Leaf of a Binary Tree
            Asked 2022-Jan-18 at 21:22

            The function above AllPaths() appends an array containing the path to each leaf of the binary tree to the global array res.

            The code works just fine, but I want to remove the global variable res and make the function return an array instead. How can I do that?

            ...

            ANSWER

            Answered 2021-Dec-26 at 20:20

            A simple way that allow you to avoid the inner lists and global list altogether is to make a generator that yields the values as they come. Then you can just pass this to list to make the final outcome:

            Source https://stackoverflow.com/questions/70489412

            QUESTION

            How can I build an immutable tree datastructure in Scala?
            Asked 2022-Jan-12 at 01:10

            I am attempting to construct an immutable Trie defined as such:

            ...

            ANSWER

            Answered 2022-Jan-12 at 01:10

            The appears to get at what you're after.

            Source https://stackoverflow.com/questions/70670816

            QUESTION

            React Route render blank page
            Asked 2021-Dec-22 at 19:09

            Here is the code screenshot.

            I want to render Homepage component but I want to wrap it into these MainLayout component.

            The problem is that screen is blank and there is no error in Terminal but when I inspect the page it says "Matched leaf route at location "/" does not have an element", so guys I know this is version update syntax problem because I had same problem when I was writing component= {component } but syntax has been changed and I should have written element={}.

            So I believe this is also syntax problem but I've done research but couldn't solve. I believe I should change this

            ...

            ANSWER

            Answered 2021-Dec-22 at 19:03

            The Route components in react-router-dom v6 no longer take component or render props; the routed components are rendered on the element prop as JSX.

            Source https://stackoverflow.com/questions/70453739

            Community Discussions, Code Snippets contain sources that include Stack Exchange Network

            Vulnerabilities

            No vulnerabilities reported

            Install Leaf

            You can download it from GitHub.
            You can use Leaf like any standard Java library. Please include the the jar files in your classpath. You can also use any IDE and you can run and debug the Leaf component as you would do with any other Java program. Best practice is to use a build tool that supports dependency management such as Maven or Gradle. For Maven installation, please refer maven.apache.org. For Gradle installation, please refer gradle.org .

            Support

            For any new features, suggestions and bugs create an issue on GitHub. If you have any questions check and ask questions on community page Stack Overflow .
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