Go语言中如何使用 compress/gzip 包进行文件压缩与解压

package main

import (
    "bytes"
    "compress/gzip"
    "fmt"
    "log"
)

func main() {
    // 原始数据
    originalData := []byte("hello, world\nThis is a test string for gzip compression.")

    // 创建一个 bytes.Buffer 作为压缩数据的目标
    var compressedBuffer bytes.Buffer

    // 创建一个 gzip.Writer，将压缩数据写入 compressedBuffer
    gzipWriter := gzip.NewWriter(&compressedBuffer)

    // 写入原始数据进行压缩
    _, err := gzipWriter.Write(originalData)
    if err != nil {
        log.Fatalf("Failed to write data to gzip writer: %v", err)
    }

    // 关闭 gzip.Writer，确保所有数据被刷新并写入文件尾
    err = gzipWriter.Close()
    if err != nil {
        log.Fatalf("Failed to close gzip writer: %v", err)
    }

    fmt.Printf("Original data length: %d bytes\n", len(originalData))
    fmt.Printf("Compressed data length: %d bytes\n", compressedBuffer.Len())
    // fmt.Printf("Compressed data (hex): %x\n", compressedBuffer.Bytes()) // 可选：查看压缩后的字节
}

package main

import (
    "bytes"
    "compress/gzip"
    "fmt"
    "io"
    "log"
)

func main() {
    // 假设 compressedBuffer 已经包含了之前压缩的数据
    originalData := []byte("hello, world\nThis is a test string for gzip compression.")
    var compressedBuffer bytes.Buffer
    gzipWriter := gzip.NewWriter(&compressedBuffer)
    _, err := gzipWriter.Write(originalData)
    if err != nil {
        log.Fatalf("Failed to write data to gzip writer: %v", err)
    }
    err = gzipWriter.Close()
    if err != nil {
        log.Fatalf("Failed to close gzip writer: %v", err)
    }
    // --- 压缩部分结束 ---

    // 创建一个 gzip.Reader 从 compressedBuffer 中读取压缩数据
    gzipReader, err := gzip.NewReader(&compressedBuffer)
    if err != nil {
        log.Fatalf("Failed to create gzip reader: %v", err)
    }
    defer gzipReader.Close() // 确保 reader 被关闭，释放资源

    // 创建一个 bytes.Buffer 来存储解压后的数据
    var decompressedBuffer bytes.Buffer

    // 将解压后的数据复制到 decompressedBuffer
    _, err = io.Copy(&decompressedBuffer, gzipReader)
    if err != nil {
        log.Fatalf("Failed to decompress data: %v", err)
    }

    fmt.Printf("Decompressed data length: %d bytes\n", decompressedBuffer.Len())
    fmt.Printf("Decompressed data:\n%s", decompressedBuffer.String())

    // 验证解压后的数据是否与原始数据一致
    if bytes.Equal(originalData, decompressedBuffer.Bytes()) {
        fmt.Println("Decompression successful: Data matches original.")
    } else {
        fmt.Println("Decompression failed: Data does not match original.")
    }
}

package main

import (
    "compress/gzip"
    "fmt"
    "io"
    "log"
    "os"
    "path/filepath"
    "strings"
)

// compressFile 将源文件压缩到目标文件
func compressFile(srcPath, destPath string) error {
    srcFile, err := os.Open(srcPath)
    if err != nil {
        return fmt.Errorf("failed to open source file %s: %w", srcPath, err)
    }
    defer srcFile.Close() // 确保源文件被关闭

    destFile, err := os.Create(destPath)
    if err != nil {
        return fmt.Errorf("failed to create destination file %s: %w", destPath, err)
    }
    defer destFile.Close() // 确保目标文件被关闭

    gzipWriter := gzip.NewWriter(destFile)
    defer gzipWriter.Close() // 确保 gzipWriter 被关闭，完成压缩

    _, err = io.Copy(gzipWriter, srcFile) // 将源文件内容复制到 gzipWriter 进行压缩
    if err != nil {
        return fmt.Errorf("failed to compress data: %w", err)
    }

    return nil
}

// decompressFile 将源Gzip文件解压到目标文件
func decompressFile(srcPath, destPath string) error {
    srcFile, err := os.Open(srcPath)
    if err != nil {
        return fmt.Errorf("failed to open source gzip file %s: %w", srcPath, err)
    }
    defer srcFile.Close() // 确保源Gzip文件被关闭

    gzipReader, err := gzip.NewReader(srcFile)
    if err != nil {
        return fmt.Errorf("failed to create gzip reader for %s: %w", srcPath, err)
    }
    defer gzipReader.Close() // 确保 gzipReader 被关闭，释放资源

    destFile, err := os.Create(destPath)
    if err != nil {
        return fmt.Errorf("failed to create destination file %s: %w", destPath, err)
    }
    defer destFile.Close() // 确保目标文件被关闭

    _, err = io.Copy(destFile, gzipReader) // 将解压后的数据复制到目标文件
    if err != nil {
        return fmt.Errorf("failed to decompress data: %w", err)
    }

    return nil
}

func main() {
    // 1. 创建一个测试文件
    originalFileName := "test_data.txt"
    originalContent := "This is some test content for the original file.\n" +
        "It spans multiple lines to demonstrate file operations.\n" +
        "Go's compress/gzip package is very efficient!"

    err := os.WriteFile(originalFileName, []byte(originalContent), 0644)
    if err != nil {
        log.Fatalf("Failed to create original file: %v", err)
    }
    fmt.Printf("Created original file: %s\n", originalFileName)

    // 2. 压缩文件
    compressedFileName := originalFileName + ".gz"
    err = compressFile(originalFileName, compressedFileName)
    if err != nil {
        log.Fatalf("Failed to compress file %s: %v", originalFileName, err)
    }
    fmt.Printf("Compressed %s to %s\n",