Optimize TUS upload: remove redundant HEAD request

opencloudApp/src/main/java/eu/opencloud/android/workers/TusUploadHelper.kt

@@ -45,6 +45,7 @@ class TusUploadHelper(
 
         var tusUrl = transfer.tusUploadUrl
         val checksumHex = transfer.tusUploadChecksum?.substringAfter("sha256:")
+        var createdOffset: Long? = null
 
         if (tusUrl.isNullOrBlank()) {
             val fileName = File(remotePath).name
@@ -69,24 +70,26 @@ class TusUploadHelper(
 
             // Use creation-with-upload like the browser does for OpenCloud compatibility
             val firstChunkSize = minOf(CreateTusUploadRemoteOperation.DEFAULT_FIRST_CHUNK, fileSize)
-            val createdLocation = executeRemoteOperation {
+            val creationResult = executeRemoteOperation {
                 CreateTusUploadRemoteOperation(
                     file = File(localPath),
                     remotePath = remotePath,
                     mimetype = mimeType,
                     metadata = metadata,
                     useCreationWithUpload = true,
+                    useCreationWithUpload = true,
                     firstChunkSize = firstChunkSize,
                     tusUrl = "",
                     collectionUrlOverride = collectionUrl,
                 ).execute(client)
             }
 
-            if (createdLocation.isNullOrBlank()) {
-                throw IllegalStateException("TUS: unable to create upload resource for $remotePath")
+            if (creationResult == null) {
+                throw java.io.IOException("TUS: unable to create upload resource for $remotePath")
             }
 
-            tusUrl = createdLocation
+            tusUrl = creationResult.uploadUrl
+            createdOffset = creationResult.uploadOffset
             val metadataString = metadata.entries.joinToString(";") { (key, value) -> "$key=$value" }
 
             transferRepository.updateTusState(
@@ -103,16 +106,20 @@ class TusUploadHelper(
 
         val resolvedTusUrl = tusUrl ?: throw IllegalStateException("TUS: missing upload URL for $remotePath")
 
-        var offset = try {
-            executeRemoteOperation {
-                GetTusUploadOffsetRemoteOperation(resolvedTusUrl).execute(client)
+        var offset = if (createdOffset != null) {
+            createdOffset
+        } else {
+            try {
+                executeRemoteOperation {
+                    GetTusUploadOffsetRemoteOperation(resolvedTusUrl).execute(client)
+                }
+            } catch (e: java.io.IOException) {
+                Timber.w(e, "TUS: failed to fetch current offset")
+                throw e
+            } catch (e: Throwable) {
+                Timber.w(e, "TUS: failed to fetch current offset")
+                0L
             }
-        } catch (e: java.io.IOException) {
-            Timber.w(e, "TUS: failed to fetch current offset")
-            throw e
-        } catch (e: Throwable) {
-            Timber.w(e, "TUS: failed to fetch current offset")
-            0L
         }.coerceAtLeast(0L)
         Timber.d("TUS: resume offset %d / %d", offset, fileSize)
         progressCallback?.invoke(offset, fileSize)

opencloudComLibrary/src/main/java/eu/opencloud/android/lib/resources/files/tus/CreateTusUploadRemoteOperation.kt

@@ -30,7 +30,12 @@ class CreateTusUploadRemoteOperation(
     private val tusUrl: String?,
     private val collectionUrlOverride: String? = null,
     private val base64Encoder: Base64Encoder = DefaultBase64Encoder()
-) : RemoteOperation<String>() {
+) : RemoteOperation<CreateTusUploadRemoteOperation.CreationResult>() {
+
+    data class CreationResult(
+        val uploadUrl: String,
+        val uploadOffset: Long
+    )
 
     interface Base64Encoder {
         fun encode(bytes: ByteArray): String
@@ -41,7 +46,7 @@ class CreateTusUploadRemoteOperation(
             Base64.encodeToString(bytes, Base64.NO_WRAP)
     }
 
-    override fun run(client: OpenCloudClient): RemoteOperationResult<String> = try {
+    override fun run(client: OpenCloudClient): RemoteOperationResult<CreationResult> = try {
         // Determine TUS endpoint URL based on provided parameters
         val targetFileUrl = if (!tusUrl.isNullOrBlank()) {
             tusUrl
@@ -135,21 +140,26 @@ class CreateTusUploadRemoteOperation(
                 val base = URL(postMethod.getFinalUrl().toString())
                 val resolved = resolveLocationToAbsolute(locationHeader, base)
 
+                val offsetHeader = postMethod.getResponseHeader(HttpConstants.UPLOAD_OFFSET)
+                val offset = offsetHeader?.toLongOrNull() ?: 0L
+
                 if (resolved != null) {
-                    Timber.d("TUS upload resource created: %s", resolved)
-                    RemoteOperationResult<String>(ResultCode.OK).apply { data = resolved }
+                    Timber.d("TUS upload resource created: %s (offset=%d)", resolved, offset)
+                    RemoteOperationResult<CreationResult>(ResultCode.OK).apply {
+                        data = CreationResult(resolved, offset)
+                    }
                 } else {
                     Timber.e("Location header is missing in TUS creation response")
-                    RemoteOperationResult<String>(IllegalStateException("Location header missing")).apply {
-                        data = ""
+                    RemoteOperationResult<CreationResult>(IllegalStateException("Location header missing")).apply {
+                        data = null
                     }
                 }
             } else {
                 Timber.w("TUS creation failed with status: %d", status)
-                RemoteOperationResult<String>(postMethod).apply { data = "" }
+                RemoteOperationResult<CreationResult>(postMethod).apply { data = null }
             }
     } catch (e: Exception) {
-        val result = RemoteOperationResult<String>(e)
+        val result = RemoteOperationResult<CreationResult>(e)
         Timber.e(e, "TUS creation operation failed")
         result
     }

opencloudComLibrary/src/test/java/eu/opencloud/android/lib/resources/files/tus/TusIntegrationTest.kt

@@ -119,12 +119,15 @@ class TusIntegrationTest {
             throw RuntimeException(msg, createResult.exception)
         }
         assertTrue("Create operation failed", createResult.isSuccess)
-        val absoluteLocation = createResult.data
-        assertNotNull(absoluteLocation)
+        val creationResult = createResult.data
+        assertNotNull(creationResult)
+        val absoluteLocation = creationResult!!.uploadUrl
+        val offset = creationResult.uploadOffset
         println("absoluteLocation: $absoluteLocation")
         println("locationPath: $locationPath")
-        println("endsWith: ${absoluteLocation!!.endsWith(locationPath)}")
+        println("endsWith: ${absoluteLocation.endsWith(locationPath)}")
         assertTrue(absoluteLocation.endsWith(locationPath))
+        assertEquals(0L, offset)
 
         // Verify POST request headers
         val postReq = server.takeRequest()