mirror of
https://github.com/VictoriaMetrics/VictoriaMetrics.git
synced 2024-12-24 03:06:48 +01:00
87c77727e4
* lib/backup/s3remote: update AWS SDK to v2 * Update lib/backup/s3remote/s3.go Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com> * lib/backup/s3remote: refactor error handling Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
68 lines
3.3 KiB
Go
68 lines
3.3 KiB
Go
// Package middleware provides transport agnostic middleware for decorating SDK
|
|
// handlers.
|
|
//
|
|
// The Smithy middleware stack provides ordered behavior to be invoked on an
|
|
// underlying handler. The stack is separated into steps that are invoked in a
|
|
// static order. A step is a collection of middleware that are injected into a
|
|
// ordered list defined by the user. The user may add, insert, swap, and remove a
|
|
// step's middleware. When the stack is invoked the step middleware become static,
|
|
// and their order cannot be modified.
|
|
//
|
|
// A stack and its step middleware are **not** safe to modify concurrently.
|
|
//
|
|
// A stack will use the ordered list of middleware to decorate a underlying
|
|
// handler. A handler could be something like an HTTP Client that round trips an
|
|
// API operation over HTTP.
|
|
//
|
|
// Smithy Middleware Stack
|
|
//
|
|
// A Stack is a collection of middleware that wrap a handler. The stack can be
|
|
// broken down into discreet steps. Each step may contain zero or more middleware
|
|
// specific to that stack's step.
|
|
//
|
|
// A Stack Step is a predefined set of middleware that are invoked in a static
|
|
// order by the Stack. These steps represent fixed points in the middleware stack
|
|
// for organizing specific behavior, such as serialize and build. A Stack Step is
|
|
// composed of zero or more middleware that are specific to that step. A step may
|
|
// define its own set of input/output parameters the generic input/output
|
|
// parameters are cast from. A step calls its middleware recursively, before
|
|
// calling the next step in the stack returning the result or error of the step
|
|
// middleware decorating the underlying handler.
|
|
//
|
|
// * Initialize: Prepares the input, and sets any default parameters as needed,
|
|
// (e.g. idempotency token, and presigned URLs).
|
|
//
|
|
// * Serialize: Serializes the prepared input into a data structure that can be
|
|
// consumed by the target transport's message, (e.g. REST-JSON serialization).
|
|
//
|
|
// * Build: Adds additional metadata to the serialized transport message, (e.g.
|
|
// HTTP's Content-Length header, or body checksum). Decorations and
|
|
// modifications to the message should be copied to all message attempts.
|
|
//
|
|
// * Finalize: Performs final preparations needed before sending the message. The
|
|
// message should already be complete by this stage, and is only alternated to
|
|
// meet the expectations of the recipient, (e.g. Retry and AWS SigV4 request
|
|
// signing).
|
|
//
|
|
// * Deserialize: Reacts to the handler's response returned by the recipient of
|
|
// the request message. Deserializes the response into a structured type or
|
|
// error above stacks can react to.
|
|
//
|
|
// Adding Middleware to a Stack Step
|
|
//
|
|
// Middleware can be added to a step front or back, or relative, by name, to an
|
|
// existing middleware in that stack. If a middleware does not have a name, a
|
|
// unique name will be generated at the middleware and be added to the step.
|
|
//
|
|
// // Create middleware stack
|
|
// stack := middleware.NewStack()
|
|
//
|
|
// // Add middleware to stack steps
|
|
// stack.Initialize.Add(paramValidationMiddleware, middleware.After)
|
|
// stack.Serialize.Add(marshalOperationFoo, middleware.After)
|
|
// stack.Deserialize.Add(unmarshalOperationFoo, middleware.After)
|
|
//
|
|
// // Invoke middleware on handler.
|
|
// resp, err := stack.HandleMiddleware(ctx, req.Input, clientHandler)
|
|
package middleware
|