kandi X-RAY | gin Summary
kandi X-RAY | gin Summary
Gin is a web framework written in Go (Golang). It features a martini-like API with performance that is up to 40 times faster thanks to httprouter. If you need performance and good productivity, you will love Gin.
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Trending Discussions on gin
How can I send a file, that I've got received from S3, to Gin as binary response?
Lets say, I have the following code to obtain an image from S3 bucket:...
ANSWERAnswered 2022-Apr-02 at 15:42
You're almost done:
ctx.Write use this one:
I am trying to speed up the querying of some json data stored inside a PostgreSQL database. I inherited an application that queries a PostgreSQL table called
data with a field called
value where value is blob of json of type
It is about 300 rows but takes 12 seconds to select this data from the 5 json elements. The json blobs are a bit large but the data I need is all in the top level of the json nesting if that helps.
I tried adding an index of
CREATE INDEX idx_tbl_data ON data USING gin (value); but that didn't help. Is there a different index I should be using? The long term vision is to re-write the application to move that data out of the json but that is something is at least 30-40 man days of work due to complexity in other parts of the application so I am looking to see if I can make this faster in short term.
Not sure if it helps but the underlying data that makes up this result set doesn't change often. It's the data that is further down in the json blob that often changes....
ANSWERAnswered 2022-Feb-12 at 12:47
Like a_horse already advised (and you mentioned yourself), the proper fix is to extract those attributes to separate columns, normalizing your design to some extent.Can an index help?
Sadly, no (as of Postgres 14).
It could work in theory. Since your values are big, an expression index with just some small attributes can be picked up by Postgres in an index-only scan, even when retrieving all rows (where it otherwise would ignore indexes).
However, PostgreSQL's planner is currently not very smart about such cases. It considers a query to be potentially executable by index-only scan only when all columns needed by the query are available from the index.
So you would have to include
value itself in the index, even if just as
INCLUDE column - totally spoiling the whole idea. No go.
You probably can still do something in the short term. Two crucial quotes:
I am looking to see if I can make this faster in short term
The json blobs are a bit large
Drop the cast to
json from the query. Casting every time adds pointless cost.
One major cost factor will be compression. Postgres has to "de-toast" the whole large column, just to extract some small attributes. Since Postgres 14, you can switch the compression algorithm (if support is enabled in your version!). The default is dictated by the config setting
default_toast_compression, which is set to
pglz by default. Currently the only available alternative is
lz4. You can set that per column. Any time.
lz4) is considerably faster, while compressing typically a bit less. About twice as fast, but around 10 % more storage (depends!). If performance is not an issue it's best to stick to the stronger compression of the default LZ algorithm (
pglz). There may be more compression algorithms to pick from in the future.
ANSWERAnswered 2022-Mar-19 at 21:55
Using middlewares is certainly not the way to go here, your hunch is correct! Using FastAPI as inspiration, I usually create models for every request/response that I have. You can then bind these models as query, path, or body models. An example of query model binding (just to show you that you can use this to more than just json post requests):
I created a logger with
kubebuilder, it is based on zap logger:
ANSWERAnswered 2022-Mar-17 at 18:11
Better answer: as suggested by @Oliver Dain, use
zap.AtomicLevel. See their answer for details.
The relevant docs:
LevelEnabler decides whether a given logging level is enabled when logging a message.
LevelEnablerFunc is a convenient way to implement zapcore.LevelEnabler with an anonymous function.
That function may then return
false based on some other variable that changes at runtime:
I've checked the documentation but it does not explain the use of setting test mode for gin...
ANSWERAnswered 2022-Mar-16 at 14:50
gin.DebugMode is used to control the output of
gin.IsDebugging(), which adds some additional log output and changes the HTML renderer to the debug struct
gin.TestMode is used in Gin's own unit tests to toggle the debug mode (and the additional logging) on and off, and the usage of the debug HTML renderer.
Other than that, it doesn't have other uses (source).
However, the flag can be controlled with the environment variable
GIN_MODE=test. Then, since
Mode() is exported, you can use it in application code to, for example, declare testing routes. This might have some merit if you plan to run an E2E test suite, or some other integration test:
I'm using the Go Gin package in my rest-API service. To add some data I used HTML file to submit the form with data. In development, it's working, but in the production build server not working, if I commented 'LoadHTMLGlob' block server working again. I think 'LoadHTMLGlob' can't load HTML. Please help to solve this issue.
my main.go file:...
ANSWERAnswered 2022-Mar-15 at 11:00
You need to add
WorkingDirectory to your system file
I have a dataset with ~ 150 countries, a grouping variable, and a value for each country and group (0-6). I am trying to show, that countries with a higher GDP get higher values in one group than the other. I made a scatterplot showing the values for each country by group (the countries are sorted by GDP). I want to draw a line around the points, so it becomes more aparent which group has higher values in which range of GDP. I am however, at a loss....
ANSWERAnswered 2022-Mar-05 at 14:03
Here's one idea to help visualize the difference you are trying to show. Firstly, the country names on the x axis are likely to remain illegible however you try to label them. It might therefore be better to have the rank of the countries on the x axis.
Drawing a polygon around the points might make the point visually, but doesn't make much sense in statistical terms. What might be better here is to plot a regression with a separate line for each group. Since we are dealing with count data, we can use Poisson regression, and since we have a numeric rank on the x axis, it is possible to have lines going across your plot to show the regression.
I have a function that handles an incoming TCP connection:...
ANSWERAnswered 2022-Feb-16 at 22:34
Create a net.Listener implementation that accepts connections by receiving on a channel:
I have the following 2 query plans for a particular query (second one was obtained by turning seqscan off):
The cost estimate for the second plan is lower than that for the first, however, pg only chooses the second plan if forced to do so (by turning seqscan off).
What could be causing this behaviour?
EDIT: Updating the question with information requested in a comment:
EXPLAIN (ANALYZE, BUFFERS, VERBOSE) for query 1 (seqscan on; does not use index). Also viewable at https://explain.depesz.com/s/cGLY:
ANSWERAnswered 2022-Feb-17 at 11:43
You should have those two indexes to speed up your query :
In my case need to catch request and check is internal request or not. If not, redirect these request to other handler function.
ANSWERAnswered 2022-Feb-17 at 13:31
Use a sub-engine.
You can instantiate an engine with
gin.New for internal routes only and not run it. Instead you pass the context from your
Any route to
This will relay the context from the main engine, and it will match path params based on the placeholders in the sub-routes.
You can declare routes on the sub-engine as usual:
No vulnerabilities reported
The first need Go installed (version 1.13+ is required), then you can use the below Go command to install Gin.
Import it in your code:
(Optional) Import net/http. This is required for example if using constants such as http.StatusOK.
Gin uses encoding/json as default json package but you can change it by build from other tags.
Gin enables MsgPack rendering feature by default. But you can disable this feature by specifying nomsgpack build tag. This is useful to reduce the binary size of executable files. See the detail information.
You can build a server into a single binary containing templates by using go-assets. See a complete example in the https://github.com/gin-gonic/examples/tree/master/assets-in-binary directory.
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