Code Explainers

Go code explainers

go 
package middleware
 
import (
	"net/http"

A per-IP rate limiter middleware in Gin

rate-limiting token-bucket middleware
Intermediate 8 steps
go 
package tsvio
 
import (
	"bufio"

Reading and writing TSV records in Go

parsing io-streams error-handling
Intermediate 10 steps
go 
package config
 
import (
	"fmt"

Loading and saving YAML config in Go

yaml struct-tags defaults
Intermediate 8 steps
go 
package theme
 
import (
	"fmt"

Per-tenant HTML templates with Gin's renderer

multi-tenancy concurrency html-templates
Advanced 8 steps
go 
package auth
 
import (
	"net/http"

Setting and reading secure session cookies in Go

cookies session-management security
Intermediate 6 steps
go 
package middleware
 
import (
	"net/http"

A maintenance-mode gate in Gin

middleware atomic-flag concurrency
Intermediate 8 steps
go 
func ServeVideo(c *gin.Context) {
	id := c.Param("id")
	video, err := videoRepo.FindByID(c.Request.Context(), id)
	if err != nil {

Streaming video files with Gin

http streaming range requests file serving
Intermediate 6 steps
go 
package handler
 
type LineItem struct {
	SKU      string  `json:"sku" binding:"required,alphanum"`

Structured validation errors in Gin

validation json-binding error-handling
Intermediate 8 steps
go 
package deepcopy
 
import (
	"bytes"

Deep copying any value with gob in Go

deep-copy serialization generics
Intermediate 6 steps
go 
package handlers
 
import (
	"net/http"

Query-string filtering in Gin with GORM

query-binding validation conditional-queries
Intermediate 8 steps
go 
func ProxyDownload(c *gin.Context) {
	objectKey := c.Param("key")
	upstream := fmt.Sprintf("%s/files/%s", storageBaseURL, objectKey)
 

Streaming a proxied download in Gin

reverse-proxy streaming http-headers
Intermediate 8 steps
go 
package handlers
 
import (
	"net/http"

Header-driven API versioning in Gin

api-versioning header-binding closures
Intermediate 6 steps
go 
func ListArticles(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		page, err := strconv.Atoi(c.DefaultQuery("page", "1"))
		if err != nil || page < 1 {

Building a paginated list endpoint in Gin

pagination query-parameters input-validation
Intermediate 8 steps
go 
package parser
 
import (
	"fmt"

Parsing access logs with named regex groups in Go

regex named-groups parsing
Intermediate 5 steps
go 
package checksum
 
import (
	"crypto/sha256"

Computing SHA-256 checksums in Go

hashing io-streaming filesystem-walk
Intermediate 7 steps
go 
package dateutil
 
import (
	"fmt"

Parsing and formatting dates in Go

date parsing layouts timezones
Intermediate 7 steps
go 
package middleware
 
import (
	"bytes"

Building a response cache middleware in Gin

middleware caching concurrency
Intermediate 8 steps
go 
package archive
 
import (
	"bytes"

Gzip round-trip compression in Go

compression io error-handling
Intermediate 5 steps