本地书籍无权限则保存到自己选定的文件夹

app/src/main/java/io/legado/app/model/localBook/TextFile.kt

@@ -1,8 +1,6 @@
 package io.legado.app.model.localBook
 
 import android.net.Uri
-import android.system.Os
-import android.system.OsConstants.SEEK_SET
 import io.legado.app.data.appDb
 import io.legado.app.data.entities.Book
 import io.legado.app.data.entities.BookChapter
@@ -11,8 +9,10 @@ import io.legado.app.help.DefaultData
 import io.legado.app.model.localBook.LocalBook.cacheFolder
 import io.legado.app.utils.*
 import splitties.init.appCtx
-import java.io.*
-import java.nio.ByteBuffer
+import java.io.File
+import java.io.FileInputStream
+import java.io.FileNotFoundException
+import java.io.FileOutputStream
 import java.nio.charset.Charset
 import java.util.regex.Matcher
 import java.util.regex.Pattern
@@ -24,73 +24,67 @@ class TextFile(private val book: Book) {
 
     @Throws(FileNotFoundException::class)
     fun getChapterList(): ArrayList<BookChapter> {
-        return getBookFD(book).let { fd ->
-            try {
-                val rulePattern = if (book.tocUrl.isNotEmpty()) {
+        var rulePattern: Pattern? = null
+        if (book.charset == null || book.tocUrl.isNotEmpty()) {
+            getBookInputStream(book).use { bis ->
+                val buffer = ByteArray(BUFFER_SIZE)
+                var blockContent: String
+                bis.read(buffer)
+                book.charset = EncodingDetect.getEncode(buffer)
+                charset = book.fileCharset()
+                blockContent = String(buffer, charset)
+                rulePattern = if (book.tocUrl.isNotEmpty()) {
                     Pattern.compile(book.tocUrl, Pattern.MULTILINE)
                 } else {
                     tocRules.addAll(getTocRules())
-                    null
+                    if (blockContent.isEmpty()) {
+                        bis.read(buffer)
+                        book.charset = EncodingDetect.getEncode(buffer)
+                        blockContent = String(buffer, charset)
+                    }
+                    getTocRule(blockContent)?.let {
+                        Pattern.compile(it.rule, Pattern.MULTILINE)
                     }
-                analyze(fd, book, rulePattern)
-            } finally {
-                if (fd.valid()) {
-                    Os.close(fd)
                 }
             }
         }
+        return analyze(rulePattern)
     }
 
-    private fun analyze(
-        bookFd: FileDescriptor,
-        book: Book,
-        pattern: Pattern?
-    ): ArrayList<BookChapter> {
+    private fun analyze(pattern: Pattern?): ArrayList<BookChapter> {
         val toc = arrayListOf<BookChapter>()
+        getBookInputStream(book).use { bis ->
             var tocRule: TxtTocRule? = null
             val buffer = ByteArray(BUFFER_SIZE)
-        var blockContent = ""
-        if (book.charset == null) {
-            Os.lseek(bookFd, 0, SEEK_SET)
-            val length = Os.read(bookFd, buffer, 0, BUFFER_SIZE)
-            book.charset = EncodingDetect.getEncode(buffer)
-            blockContent = String(buffer, 0, length, charset)
-            charset = book.fileCharset()
-        }
+            var blockContent: String
             val rulePattern = pattern ?: let {
-            if (blockContent.isEmpty()) {
-                Os.lseek(bookFd, 0, SEEK_SET)
-                val length = Os.read(bookFd, buffer, 0, BUFFER_SIZE)
-                blockContent = String(buffer, 0, length, charset)
-            }
+                val length = bis.read(buffer)
+                bis.skip(-length.toLong())
+                blockContent = String(buffer, charset)
                 tocRule = getTocRule(blockContent)
                 tocRule?.let {
                     Pattern.compile(it.rule, Pattern.MULTILINE)
                 }
             }
             //加载章节
-        //获取到的块起始点，在文件中的位置
-        Os.lseek(bookFd, 0, SEEK_SET)
             var curOffset: Long = 0
             //block的个数
             var blockPos = 0
             //读取的长度
             var length: Int
-        var allLength = 0
-        val xx = ByteBuffer.allocate(BUFFER_SIZE)
             //获取文件中的数据到buffer，直到没有数据为止
-        while (Os.read(bookFd, xx).also { length = it } > 0) {
+            while (bis.read(buffer).also { length = it } > 0) {
                 blockPos++
                 //如果存在Chapter
                 if (rulePattern != null) {
                     //将数据转换成String, 不能超过length
-                blockContent = String(xx.array(), 0, length, charset)
+                    blockContent = String(buffer, 0, length, charset)
                     val lastN = blockContent.lastIndexOf("\n")
                     if (lastN > 0) {
                         blockContent = blockContent.substring(0, lastN)
-                    length = blockContent.toByteArray(charset).size
-                    allLength += length
-                    Os.lseek(bookFd, allLength.toLong(), SEEK_SET)
+                        val blockContentSize = blockContent.toByteArray(charset).size
+                        bis.skip(-(length - blockContentSize).toLong())
+                        length = blockContentSize
                     }
                     //当前Block下使过的String的指针
                     var seekPos = 0
@@ -106,7 +100,8 @@ class TextFile(private val book: Book) {
                         if (curOffset + chapterLength - lastStart > 50000 && pattern == null) {
                             //移除不匹配的规则
                             tocRules.remove(tocRule)
-                        return analyze(bookFd, book, null)
+                            bis.close()
+                            return analyze(null)
                         }
                         //如果 seekPos == 0 && nextChapterPos != 0 表示当前block处前面有一段内容
                         //第一种情况一定是序章 第二种情况是上一个章节的内容
@@ -162,7 +157,8 @@ class TextFile(private val book: Book) {
                     if (seekPos == 0 && length > 50000 && pattern == null) {
                         //移除不匹配的规则
                         tocRules.remove(tocRule)
-                    return analyze(bookFd, book, null)
+                        bis.close()
+                        return analyze(null)
                     }
                 } else { //进行本地虚拟分章
                     //章节在buffer的偏移量
@@ -218,6 +214,10 @@ class TextFile(private val book: Book) {
                     System.runFinalization()
                 }
             }
+            tocRule?.let {
+                book.tocUrl = it.rule
+            }
+        }
         for (i in toc.indices) {
             val bean = toc[i]
             bean.index = i
@@ -229,9 +229,7 @@ class TextFile(private val book: Book) {
 
         System.gc()
         System.runFinalization()
-        tocRule?.let {
-            book.tocUrl = it.rule
-        }
+
         return toc
     }
 
@@ -241,18 +239,22 @@ class TextFile(private val book: Book) {
     private fun getTocRule(content: String): TxtTocRule? {
         var txtTocRule: TxtTocRule? = null
         var maxCs = 0
-        for (tocRule in tocRules) {
+        val removeRules = hashSetOf<TxtTocRule>()
+        tocRules.forEach { tocRule ->
             val pattern = Pattern.compile(tocRule.rule, Pattern.MULTILINE)
             val matcher = pattern.matcher(content)
             var cs = 0
             while (matcher.find()) {
                 cs++
             }
-            if (cs > maxCs) {
+            if (cs == 0) {
+                removeRules.add(tocRule)
+            } else if (cs > maxCs) {
                 maxCs = cs
                 txtTocRule = tocRule
             }
         }
+        tocRules.removeAll(removeRules)
         return txtTocRule
     }
 
@@ -274,22 +276,18 @@ class TextFile(private val book: Book) {
         @Throws(FileNotFoundException::class)
         fun getContent(book: Book, bookChapter: BookChapter): String {
             val count = (bookChapter.end!! - bookChapter.start!!).toInt()
-            val content = ByteArray(count)
-            getBookFD(book).let { fd ->
-                try {
-                    Os.lseek(fd, bookChapter.start!!, SEEK_SET)
-                    Os.read(fd, content, 0, count)
-                } finally {
-                    Os.close(fd)
-                }
+            val buffer = ByteArray(count)
+            getBookInputStream(book).use { bis ->
+                bis.skip(bookChapter.start!!)
+                bis.read(buffer)
             }
-            return String(content, book.fileCharset())
+            return String(buffer, book.fileCharset())
                 .substringAfter(bookChapter.title)
                 .replace("^[\\n\\s]+".toRegex(), "　　")
         }
 
         @Throws(FileNotFoundException::class)
-        private fun getBookFD(book: Book): FileDescriptor {
+        private fun getBookInputStream(book: Book): FileInputStream {
             if (book.bookUrl.isContentScheme()) {
                 val uri = Uri.parse(book.bookUrl)
                 val bookFile = cacheFolder.getFile(book.name)
@@ -302,10 +300,10 @@ class TextFile(private val book: Book) {
                         }
                     }
                 }
-                return FileInputStream(bookFile).fd
+                return FileInputStream(bookFile)
                 //return appCtx.contentResolver.openFileDescriptor(uri, "r")!!.fileDescriptor
             }
-            return FileInputStream(File(book.bookUrl)).fd
+            return FileInputStream(File(book.bookUrl))
         }
 
         private fun getTocRules(): List<TxtTocRule> {