Fix #165, use fast conversion, add tests

mirai-core-qqandroid/src/commonMain/kotlin/net/mamoe/mirai/qqandroid/message/convension.kt

@@ -173,7 +173,8 @@ internal fun MsgComm.Msg.toMessageChain(): MessageChain {
     }.cleanupRubbishMessageElements()
 }
 
-// These two functions are not identical, dont combine.
+// These two functions have difference method signature, don't combine.
+
 @OptIn(ExperimentalUnsignedTypes::class, MiraiInternalAPI::class)
 internal fun ImMsgBody.SourceMsg.toMessageChain(): MessageChain {
     val elements = this.elems!!
@@ -218,6 +219,7 @@ internal inline fun <reified R> Iterable<*>.firstIsInstance(): R {
 
 @OptIn(MiraiInternalAPI::class, LowLevelAPI::class)
 internal fun List<ImMsgBody.Elem>.joinToMessageChain(message: MessageChainBuilder) {
+    // (this._miraiContentToString())
     this.forEach {
         when {
             it.srcMsg != null -> message.add(QuoteReply(MessageSourceFromServer(it.srcMsg)))
@@ -277,7 +279,7 @@ internal fun List<ImMsgBody.Elem>.joinToMessageChain(message: MessageChainBuilde
                 }
             }
             else -> {
-                println(it._miraiContentToString())
+                // println(it._miraiContentToString())
             }
         }
     }

mirai-core/src/commonMain/kotlin/net.mamoe.mirai/message/data/Image.kt

@@ -21,7 +21,6 @@ import net.mamoe.mirai.BotImpl
 import net.mamoe.mirai.contact.Contact
 import net.mamoe.mirai.contact.Group
 import net.mamoe.mirai.utils.MiraiInternalAPI
-import net.mamoe.mirai.utils.io.chunkedHexToBytes
 import kotlin.js.JsName
 import kotlin.jvm.JvmMultifileClass
 import kotlin.jvm.JvmName
@@ -52,9 +51,9 @@ interface Image : Message, MessageContent {
 @Suppress("FunctionName")
 @JsName("newImage")
 @JvmName("newImage")
-fun Image(imageId: String): Image = when (imageId.length) {
-    54, 37 -> OfflineFriendImage(imageId) // /f8f1ab55-bf8e-4236-b55e-955848d7069f
-    42 -> OfflineGroupImage(imageId) // {01E9451B-70ED-EAE3-B37C-101F1EEBF5B5}.png
+fun Image(imageId: String): Image = when {
+    imageId.startsWith('/') -> OfflineFriendImage(imageId) // /f8f1ab55-bf8e-4236-b55e-955848d7069f
+    imageId.length == 42 || imageId.startsWith('{') && imageId.endsWith('}') -> OfflineGroupImage(imageId) // {01E9451B-70ED-EAE3-B37C-101F1EEBF5B5}.png
     else -> throw IllegalArgumentException("Bad imageId, expecting length=37 or 42, got ${imageId.length}")
 }
 
@@ -272,21 +271,71 @@ abstract class OnlineFriendImage : FriendImage(), OnlineImage
 
 private val EMPTY_BYTE_ARRAY = ByteArray(0)
 
-private fun calculateImageMd5ByImageId(imageId: String): ByteArray {
-    return if (imageId.startsWith('/')) {
-        imageId
-            .drop(1)
-            .replace("-", "")
-            .take(16 * 2)
-            .chunkedHexToBytes()
+
+// /000000000-3814297509-BFB7027B9354B8F899A062061D74E206
+private val FRIEND_IMAGE_ID_REGEX_1 = Regex("""/[0-9]*-[0-9]*-[0-9a-zA-Z]{32}""")
+
+// /f8f1ab55-bf8e-4236-b55e-955848d7069f
+private val FRIEND_IMAGE_ID_REGEX_2 = Regex("""/.{8}-(.{4}-){3}.{12}""")
+
+// {01E9451B-70ED-EAE3-B37C-101F1EEBF5B5}.png
+private val GROUP_IMAGE_ID_REGEX = Regex("""\{.{8}-(.{4}-){3}.{12}}\..*""")
+
+@Suppress("NOTHING_TO_INLINE") // no stack waste
+internal inline fun Char.hexDigitToByte(): Int {
+    return when (this) {
+        in '0'..'9' -> this - '0'
+        in 'A'..'F' -> 10 + (this - 'A')
+        in 'a'..'f' -> 10 + (this - 'a')
+        else -> throw IllegalArgumentException("illegal hex digit: $this")
+    }
+}
+
+internal fun String.skipToSecondHyphen(): Int {
+    var count = 0
+    this.forEachIndexed { index, c ->
+        if (c == '-' && ++count == 2) return index
+    }
+    error("cannot find two hyphens")
+}
+
+internal fun String.imageIdToMd5(offset: Int): ByteArray {
+    val result = ByteArray(16)
+    var cur = 0
+    var hasCurrent = false
+    var lastChar: Char = 0.toChar()
+    for (index in offset..this.lastIndex) {
+        val char = this[index]
+        if (char == '-') continue
+        if (hasCurrent) {
+            result[cur++] = (lastChar.hexDigitToByte().shl(4) or char.hexDigitToByte()).toByte()
+            if (cur == 16) return result
+            hasCurrent = false
         } else {
-        imageId
-            .substringAfter('{')
-            .substringBefore('}')
-            .replace("-", "")
-            .take(16 * 2)
-            .chunkedHexToBytes()
+            lastChar = char
+            hasCurrent = true
+        }
+    }
+    error("No enough chars")
+}
+
+@OptIn(ExperimentalStdlibApi::class)
+internal fun calculateImageMd5ByImageId(imageId: String): ByteArray {
+    return when {
+        imageId.matches(FRIEND_IMAGE_ID_REGEX_1) -> imageId.imageIdToMd5(imageId.skipToSecondHyphen() + 1)
+        imageId.matches(FRIEND_IMAGE_ID_REGEX_2) ->
+            imageId.imageIdToMd5(1)
+        imageId.matches(GROUP_IMAGE_ID_REGEX) -> {
+            imageId.imageIdToMd5(1)
+        }
+        else -> error(
+            "illegal imageId: $imageId. " +
+                    "ImageId must matches Regex `${FRIEND_IMAGE_ID_REGEX_1.pattern}`, " +
+                    "`${FRIEND_IMAGE_ID_REGEX_2.pattern}` or " +
+                    "`${GROUP_IMAGE_ID_REGEX.pattern}`"
+        )
     }
 }
 
+
 // endregion
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mirai-core/src/commonTest/kotlin/net/mamoe/mirai/message.data/ImageTest.kt

+/*
+ * Copyright 2020 Mamoe Technologies and contributors.
+ *
+ * 此源代码的使用受 GNU AFFERO GENERAL PUBLIC LICENSE version 3 许可证的约束, 可以在以下链接找到该许可证.
+ * Use of this source code is governed by the GNU AGPLv3 license that can be found through the following link.
+ *
+ * https://github.com/mamoe/mirai/blob/master/LICENSE
+ */
+
+package net.mamoe.mirai.message.data
+
+import net.mamoe.mirai.utils.io.autoHexToBytes
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertFailsWith
+
+internal class ImageTest {
+
+    @Test
+    fun testHexDigitToByte() {
+        assertEquals(0xf, 'f'.hexDigitToByte())
+        assertEquals(0x1, '1'.hexDigitToByte())
+        assertEquals(0x0, '0'.hexDigitToByte())
+        assertFailsWith<IllegalArgumentException> {
+            'g'.hexDigitToByte()
+        }
+    }
+
+    @Test
+    fun testCalculateImageMd5ByImageId() {
+        assertEquals(
+            "01E9451B-70ED-EAE3-B37C-101F1EEBF5B5".filterNot { it == '-' }.autoHexToBytes().contentToString(),
+            calculateImageMd5ByImageId("{01E9451B-70ED-EAE3-B37C-101F1EEBF5B5}.png").contentToString()
+        )
+
+        assertEquals(
+            "f8f1ab55-bf8e-4236-b55e-955848d7069f".filterNot { it == '-' }.autoHexToBytes().contentToString(),
+            calculateImageMd5ByImageId("/f8f1ab55-bf8e-4236-b55e-955848d7069f").contentToString()
+        )
+
+        assertEquals(
+            "BFB7027B9354B8F899A062061D74E206".filterNot { it == '-' }.autoHexToBytes().contentToString(),
+            calculateImageMd5ByImageId("/000000000-3814297509-BFB7027B9354B8F899A062061D74E206").contentToString()
+        )
+
+    }
+
+    //  `/f8f1ab55-bf8e-4236-b55e-955848d7069f` 或 `/000000000-3814297509-BFB7027B9354B8F899A062061D74E206`
+}
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