支持提供crc32哈希算法的结构文件

src/main/kotlin/File2.kt

@@ -1,16 +1,17 @@
-//@file:JvmName("FileObj")
+@file:JvmName("File2")
 
 import java.io.File
 import java.io.FileInputStream
 import java.io.FileNotFoundException
 import java.io.FileOutputStream
 import java.nio.file.Paths
 import java.security.MessageDigest
+import java.util.zip.CRC32
 import kotlin.io.path.pathString
 
 class File2 : Iterable<File2>
 {
-    private var file: File
+    var file: File
 
     constructor(file: String): this(File(file))
 
@@ -178,38 +179,57 @@ class File2 : Iterable<File2>
 
     val md5: String get() = hash("MD5")
 
-    private fun hash(method: String): String
-    {
-        val bufferLen = { filelen: Long ->
-            val kb = 1024
-            val mb = 1024 * 1024
-            val gb = 1024 * 1024 * 1024
-            when {
-                filelen < 1 * mb -> 8 * kb
-                filelen < 2 * mb -> 16 * kb
-                filelen < 4 * mb -> 32 * kb
-                filelen < 8 * mb -> 64 * kb
-                filelen < 16 * mb -> 256 * kb
-                filelen < 32 * mb -> 512 * kb
-                filelen < 64 * mb -> 1 * mb
-                filelen < 128 * mb -> 2 * mb
-                filelen < 256 * mb -> 4 * mb
-                filelen < 512 * mb -> 8 * mb
-                filelen < 1 * gb -> 16 * mb
-                else -> 32 * mb
-            }
+    val crc32: String get() {
+        val crc32calculator = CRC32()
+        FileInputStream(file).use {
+            var len = 0
+            val buf = ByteArray(chooseBufferLength(length))
+            while (it.read(buf).also { len = it } != -1)
+                crc32calculator.update(buf, 0, len)
         }
 
+        val value = crc32calculator.value
+        val array = ByteArray(4)
+        array[3] = (value shr (8 * 0) and 0xFF).toByte()
+        array[2] = (value shr (8 * 1) and 0xFF).toByte()
+        array[1] = (value shr (8 * 2) and 0xFF).toByte()
+        array[0] = (value shr (8 * 3) and 0xFF).toByte()
+        return bin2str(array)
+    }
+
+    private fun hash(method: String): String
+    {
         val md = MessageDigest.getInstance(method)
         FileInputStream(file).use {
             var len = 0
-            val buf = ByteArray(bufferLen(length))
+            val buf = ByteArray(chooseBufferLength(length))
             while (it.read(buf).also { len = it } != -1)
                 md.update(buf, 0, len)
         }
         return bin2str(md.digest())
     }
 
+    private fun chooseBufferLength(length: Long): Int
+    {
+        val kb = 1024
+        val mb = 1024 * 1024
+        val gb = 1024 * 1024 * 1024
+        return when {
+            length < 1 * mb -> 8 * kb
+            length < 2 * mb -> 16 * kb
+            length < 4 * mb -> 32 * kb
+            length < 8 * mb -> 64 * kb
+            length < 16 * mb -> 256 * kb
+            length < 32 * mb -> 512 * kb
+            length < 64 * mb -> 1 * mb
+            length < 128 * mb -> 2 * mb
+            length < 256 * mb -> 4 * mb
+            length < 512 * mb -> 8 * mb
+            length < 1 * gb -> 16 * mb
+            else -> 32 * mb
+        }
+    }
+
     private fun bin2str(binary: ByteArray): String
     {
         fun cvt (num: Byte): String

src/main/kotlin/FileDiff.kt

@@ -6,7 +6,7 @@
  * @param base 基准目录，用来计算相对路径
  * @param hashCacher hash缓存对象
  */
-class FileDiff(val current: VirtualFile, val contrast: File2, val base: File2, val hashCacher: HashCacher)
+class FileDiff(val current: VirtualFile, val contrast: File2, val base: File2, val hashCacher: HashCacher, val useSha1: Boolean)
 {
     private val differences: Difference = Difference()
 
@@ -22,7 +22,7 @@ class FileDiff(val current: VirtualFile, val contrast: File2, val base: File2, v
 
             if(corresponding == null) // 如果文件不存在的话，就不用校验了，可以直接进行下载
             {
-                markAsNew(VirtualFile.fromRealFile(c), c)
+                markAsNew(VirtualFile.fromRealFile(c, useSha1), c)
                 continue
             }
 
@@ -81,7 +81,7 @@ class FileDiff(val current: VirtualFile, val contrast: File2, val base: File2, v
         if(a.modified == b.modified)
             return true
 
-        return if(hashCacher.getHash(b.relativizedBy(base)) != a.hash) {
+        return if(hashCacher.getHash(b.relativizedBy(base), useSha1) != a.hash) {
             false
         } else {
             b._file.setLastModified(a.modified)

src/main/kotlin/HashCacher.kt

@@ -7,14 +7,17 @@ class HashCacher(val base: File2)
 {
     private val cache = mutableMapOf<String, String>()
 
-    fun getHash(relativePath: String): String
+    fun getHash(relativePath: String, useSha1: Boolean): String
     {
-        if (relativePath !in cache)
+        val key = (if (useSha1) "sha1|" else "crc32|") + relativePath
+
+        if (key !in cache)
         {
             val file = base + relativePath
-            cache[relativePath] = file.sha1
+            cache[key] = if (useSha1) file.sha1 else file.crc32
+            println(cache[key])
         }
 
-        return cache[relativePath]!!
+        return cache[key]!!
     }
 }

src/main/kotlin/Server.kt

@@ -9,7 +9,8 @@ import kotlin.collections.LinkedHashMap
 class Server(val config: AppConfig) : NanoHTTPD(config.host, config.port)
 {
     private val fmt = SimpleDateFormat("YYYY-MM-dd HH:mm:ss")
-    private var structureInfoCache: String? = null
+    private var structureCacheInSha1: String? = null
+    private var structureCacheInCrc32: String? = null
 
     /**
      * 服务主函数
@@ -51,11 +52,16 @@ class Server(val config: AppConfig) : NanoHTTPD(config.host, config.port)
             {
                 val ne = LinkedHashMap<String, Any>()
                 ne["update"] = "res"
-                ne.putAll(config.configYaml.filter { it.key == "common_mode" || it.key == "once_mode" })
+                ne["common_mode"] = config.configYaml["common_mode"] as List<*>
+                ne["once_mode"] = config.configYaml["once_mode"] as List<*>
+                ne["hash_algorithm"] = "crc32"
                 return ResponseHelper.buildJsonTextResponse(JSONObject(ne).toString(4))
             } else if (path == "/res.json") {
-                regenResCache()
-                return ResponseHelper.buildJsonTextResponse(structureInfoCache!!)
+                regenResSha1Cache()
+                return ResponseHelper.buildJsonTextResponse(structureCacheInSha1!!)
+            } else if (path == "/res_crc32.json") {
+                regenResCrc32Cache()
+                return ResponseHelper.buildJsonTextResponse(structureCacheInCrc32!!)
             } else if (dir != null) { // 禁止访问任何目录
                 return ResponseHelper.buildForbiddenResponse("Directory is unable to show")
             } else if (!path.startsWith("/res/")) { // 不能访问res目录以外的文件
@@ -80,26 +86,34 @@ class Server(val config: AppConfig) : NanoHTTPD(config.host, config.port)
     }
 
     /**
-     * 生成res目录缓存
+     * 生成res目录缓存（sha1算法）
      */
-    private fun regenResCache()
+    private fun regenResSha1Cache()
     {
-        structureInfoCache = JSONArray().also { j -> genCache(config.baseDir + "res").forEach { j.put(it.toJsonObject()) } }.toString()
+        structureCacheInSha1 = JSONArray().also { j -> genCache(config.baseDir + "res", true).forEach { j.put(it.toJsonObject()) } }.toString()
+    }
+
+    /**
+     * 生成res目录缓存（crc32算法）
+     */
+    private fun regenResCrc32Cache()
+    {
+        structureCacheInCrc32 = JSONArray().also { j -> genCache(config.baseDir + "res", false).forEach { j.put(it.toJsonObject()) } }.toString()
     }
 
     /**
      * 生成文件结构信息
      */
-    private fun genCache(directory: File2): List<VirtualFile>
+    private fun genCache(directory: File2, useSha1: Boolean): List<VirtualFile>
     {
         fun getDirname(path: String): String? = path.lastIndexOf("/").run { if (this == -1) null else path.substring(0, this) }
         fun getBasename(path: String): String = path.lastIndexOf("/").run { if (this == -1) path else path.substring(this + 1) }
 
         val baseDir = config.baseDir + "res"
         val hashCacher = HashCacher(baseDir)
-        val cacheFile = File2("cache.json")
+        val cacheFile = File2(if (useSha1) "cache.json" else "cache_crc32.json")
         val cache = cacheFile.run { if (exists) VirtualFile.fromJsonArray(JSONArray(content), "no_name") else null }
-        val diff = cache?.run { FileDiff(this, directory, baseDir, hashCacher).compare() }
+        val diff = cache?.run { FileDiff(this, directory, baseDir, hashCacher, useSha1).compare() }
 
         // 更新res.json缓存
         if (diff?.hasDifferences() == true)
@@ -133,13 +147,13 @@ class Server(val config: AppConfig) : NanoHTTPD(config.host, config.port)
                 val file = baseDir + f
                 val length = file.length
                 val modified = file.modified
-                val hash = hashCacher.getHash(f)
+                val hash = hashCacher.getHash(f, useSha1)
 
                 dir.files += VirtualFile(filename, length, hash, modified)
             }
         }
 
-        val result = cache?.files ?: VirtualFile.fromRealFile(directory).files
+        val result = cache?.files ?: VirtualFile.fromRealFile(directory, useSha1).files
 
         // 落盘
         if (diff == null || diff.hasDifferences())

src/main/kotlin/VirtualFile.kt

@@ -129,12 +129,12 @@ class VirtualFile
         }
 
         @JvmStatic
-        fun fromRealFile(file: File2): VirtualFile
+        fun fromRealFile(file: File2, useSha1: Boolean): VirtualFile
         {
             return if (file.isDirectory) {
-                VirtualFile(file.name, files = file.files.map { fromRealFile(it) })
+                VirtualFile(file.name, files = file.files.map { fromRealFile(it, useSha1) })
             } else {
-                VirtualFile(file.name, length = file.length, hash = file.sha1, modified = file.modified)
+                VirtualFile(file.name, length = file.length, hash = if (useSha1) file.sha1 else file.crc32, modified = file.modified)
             }
         }
     }