Polish download defaults and align CLI configuration

app/shared/src/commonTest/kotlin/com/linroid/ketch/app/util/RowContentTest.kt

@@ -124,8 +124,12 @@ class RowContentTest {
   @Test
   fun rowContent_queued_explainsWait() = runTest {
     val running = listOf(DownloadRequest("https://a.com/1"), DownloadRequest("https://b.com/2"))
+    val fullQueue = context.copy(
+      config = DownloadConfig(maxConcurrentDownloads = 2),
+      running = running,
+    )
 
-    val waiting = rowContent(request, DownloadState.Queued, now, context.copy(running = running))
+    val waiting = rowContent(request, DownloadState.Queued, now, fullQueue)
     val unknown = rowContent(request, DownloadState.Queued, now, context.copy(config = null))
 
     assertEquals("Waiting for a free slot (2 of 2 in use)", waiting.detail.load())
@@ -146,7 +150,11 @@ class RowContentTest {
   @Test
   fun rowContent_queuedWithPositionThree_saysTwoAhead() = runTest {
     val running = listOf(DownloadRequest("https://a.com/1"), DownloadRequest("https://b.com/2"))
-    val capable = context.copy(running = running, features = KetchFeatures.ALL)
+    val capable = context.copy(
+      config = DownloadConfig(maxConcurrentDownloads = 2),
+      running = running,
+      features = KetchFeatures.ALL,
+    )
 
     val content = rowContent(request, DownloadState.Queued, now, capable, queuePosition = 3)
 

cli/README.md

@@ -91,7 +91,7 @@ command exits when the download completes or fails.
 |---|---|
 | `--speed-limit <value>` | Limit download speed (e.g., `500k`, `1m`, `10m`) |
 | `--priority <level>` | Set download priority: `low`, `normal`, `high`, `urgent` |
-| `--max-concurrent <n>` | Max simultaneous downloads (default: 3) |
+| `--max-concurrent <n>` | Max simultaneous downloads (default: 4) |
 | `-H`, `--header <header>` | Send a request header, as `'Name: value'`; repeatable |
 | `--user-agent <value>` | Send this `User-Agent` instead of `Ketch/<version>` |
 | `--referer <url>` | Send this `Referer` |
@@ -468,8 +468,9 @@ port = 8642
 # defaultDirectory = "~/Downloads"  # ~ is your home folder
 # speedLimit = "unlimited"  # "unlimited", "10m" (MB/s), "500k" (KB/s)
 maxConnectionsPerDownload = 4
-maxConcurrentDownloads = 2
-maxConnectionsPerHost = 8
+# Queue limits count downloads, not individual connections; 0 means unlimited.
+maxConcurrentDownloads = 4
+maxConnectionsPerHost = 16
 
 # Advanced settings (defaults are usually fine):
 # retryCount = 3
@@ -519,8 +520,8 @@ maxConnectionsPerHost = 8
 | `defaultDirectory` | string | `~/Downloads` | Default save directory; a leading `~` is your home folder |
 | `speedLimit` | string | `"unlimited"` | Global speed limit (`"500k"`, `"10m"`, or bytes) |
 | `maxConnectionsPerDownload` | int | `4` | Connections (segments) per HTTP or FTP download |
-| `maxConcurrentDownloads` | int | `2` | Max simultaneous downloads (`0` = unlimited) |
-| `maxConnectionsPerHost` | int | `8` | Max simultaneous downloads per host (`0` = unlimited) |
+| `maxConcurrentDownloads` | int | `4` | Max simultaneous downloads (`0` = unlimited) |
+| `maxConnectionsPerHost` | int | `16` | Max simultaneous downloads per host (`0` = unlimited) |
 | `retryCount` | int | `3` | Max automatic retries after a retryable failure |
 | `retryDelayMs` | long | `1000` | Base delay between retries (exponential backoff) |
 | `progressIntervalMs` | long | `200` | Progress update throttle interval |

cli/src/main/kotlin/com/linroid/ketch/cli/DownloadArgs.kt

@@ -1,6 +1,7 @@
 package com.linroid.ketch.cli
 
 import com.linroid.ketch.api.Destination
+import com.linroid.ketch.api.DownloadConfig
 import com.linroid.ketch.api.DownloadPriority
 import com.linroid.ketch.api.DownloadRequest
 import com.linroid.ketch.api.SpeedLimit
@@ -21,7 +22,7 @@ internal sealed interface DownloadArgs {
     val destination: String?,
     val speedLimit: SpeedLimit = SpeedLimit.Unlimited,
     val priority: DownloadPriority = DownloadPriority.NORMAL,
-    val maxConcurrent: Int = 3,
+    val maxConcurrent: Int = DownloadConfig.Default.maxConcurrentDownloads,
     val headers: Map<String, String> = emptyMap(),
   ) : DownloadArgs
 }
@@ -45,7 +46,7 @@ internal fun parseDownloadArgs(args: List<String>): DownloadArgs {
   var destination: String? = null
   var speedLimit = SpeedLimit.Unlimited
   var priority = DownloadPriority.NORMAL
-  var maxConcurrent = 3
+  var maxConcurrent = DownloadConfig.Default.maxConcurrentDownloads
   val headers = LinkedHashMap<String, String>()
   // Header names ignore case, so a later option replaces an earlier one however it is spelled.
   fun setHeader(name: String, value: String) {

cli/src/main/kotlin/com/linroid/ketch/cli/Main.kt

@@ -116,10 +116,6 @@ private fun runDownload(args: DownloadArgs.Download) {
   println()
 
   val config = DownloadConfig(
-    maxConnectionsPerDownload = 4,
-    retryCount = 3,
-    retryDelayMs = 1000,
-    progressIntervalMs = 200,
     maxConcurrentDownloads = args.maxConcurrent,
   )
 

cli/src/test/kotlin/com/linroid/ketch/cli/DownloadArgsTest.kt

@@ -1,6 +1,7 @@
 package com.linroid.ketch.cli
 
 import com.linroid.ketch.api.Destination
+import com.linroid.ketch.api.DownloadConfig
 import com.linroid.ketch.api.DownloadPriority
 import com.linroid.ketch.api.SpeedLimit
 import java.io.File
@@ -10,6 +11,16 @@ import kotlin.test.assertIs
 
 class DownloadArgsTest {
 
+  @Test
+  fun parseDownloadArgs_withoutQueueOverride_usesSharedDownloadDefault() {
+    val parsed = parseDownloadArgs(listOf("https://example.com/a.zip"))
+
+    assertEquals(
+      DownloadConfig.Default.maxConcurrentDownloads,
+      assertIs<DownloadArgs.Download>(parsed).maxConcurrent,
+    )
+  }
+
   @Test
   fun `help flags print usage instead of downloading`() {
     assertEquals(DownloadArgs.Help, parseDownloadArgs(listOf("--help")))

config/src/jvmMain/kotlin/com/linroid/ketch/config/DefaultConfig.kt

@@ -35,8 +35,9 @@ port = 8642
 # defaultDirectory = "~/Downloads"  # ~ is your home folder
 # speedLimit = "unlimited"  # "unlimited", "10m" (MB/s), "500k" (KB/s)
 maxConnectionsPerDownload = 4
-maxConcurrentDownloads = 2
-maxConnectionsPerHost = 8
+# Queue limits count downloads, not individual connections; 0 means unlimited.
+maxConcurrentDownloads = 4
+maxConnectionsPerHost = 16
 
 # Advanced settings (defaults are usually fine):
 # retryCount = 3

config/src/jvmTest/kotlin/com/linroid/ketch/config/DefaultConfigTest.kt

@@ -1,5 +1,6 @@
 package com.linroid.ketch.config
 
+import com.linroid.ketch.api.DownloadConfig
 import java.io.File
 import kotlin.io.path.createTempDirectory
 import kotlin.test.Test
@@ -13,6 +14,7 @@ class DefaultConfigTest {
       KetchConfig.serializer(),
       DEFAULT_CONFIG_CONTENT,
     )
+    assertEquals(DownloadConfig.Default, decoded.download)
     assertEquals(TorrentSettings(), decoded.torrent)
     assertEquals(8642, decoded.server.port)
   }
@@ -29,6 +31,10 @@ class DefaultConfigTest {
 
       val home = System.getProperty("user.home").trimEnd('/', '\\')
       assertEquals("$home/Downloads", config.download.defaultDirectory)
+      assertEquals(
+        DownloadConfig.Default.copy(defaultDirectory = "$home/Downloads"),
+        config.download,
+      )
       // Ktor's CORS allowHost rejects a scheme in the host, failing server startup
       assertEquals(listOf("localhost:3000"), config.server.corsAllowedHosts)
       assertEquals(listOf("$home/Media"), config.server.allowedDirectories)

docs/api.md

@@ -235,8 +235,8 @@ DownloadConfig(
   saveIntervalMs = 5000,          // how often segment progress is persisted
   bufferSize = 8192,              // FTP read buffer size
   speedLimit = SpeedLimit.kbps(500), // global speed limit (default: Unlimited)
-  maxConcurrentDownloads = 2,     // max simultaneous downloads (0 = unlimited)
-  maxConnectionsPerHost = 8,      // max simultaneous downloads per host (0 = unlimited)
+  maxConcurrentDownloads = 4,     // max simultaneous downloads (0 = unlimited)
+  maxConnectionsPerHost = 16,     // max simultaneous downloads per host (0 = unlimited)
 )
 ```
 
@@ -252,7 +252,10 @@ downloads that start or resume afterwards; pause and resume a running download t
 A changed `defaultDirectory` that does not exist or is not a folder is rejected with
 `IllegalArgumentException`, and the previous configuration stays in effect.
 
-The per-host limit counts downloads by URL host (case-insensitive, ignoring user info and port).
+The per-host limit counts downloads by URL host (case-insensitive, ignoring user info and port),
+not their individual connections. With the defaults, the global limit of four downloads applies
+before the per-host limit of sixteen. Explicit values in an existing configuration are kept;
+omitted fields use the current defaults.
 Magnet links, `torrent:` identifiers and local files are not counted.
 
 `maxConnectionsPerDownload` and `DownloadRequest.connections` split HTTP(S) and FTP(S)

library/api/src/commonMain/kotlin/com/linroid/ketch/api/DownloadConfig.kt

@@ -5,6 +5,9 @@ import kotlinx.serialization.Serializable
 /**
  * Global download configuration.
  *
+ * Defaults allow four downloads at once, at most sixteen per host, and four connections per
+ * HTTP(S) or FTP(S) download. The per-host limit counts tasks, not their individual connections.
+ *
  * Can be replaced at runtime with [KetchApi.updateConfig]. [speedLimit],
  * [maxConcurrentDownloads] and [maxConnectionsPerHost] apply immediately. Every other field
  * is read when a download starts or resumes, so a running download keeps the values it
@@ -45,14 +48,14 @@ import kotlinx.serialization.Serializable
 data class DownloadConfig(
   val defaultDirectory: String? = null,
   val retryCount: Int = 3,
-  val retryDelayMs: Long = 1000,
+  val retryDelayMs: Long = 1_000,
   val progressIntervalMs: Long = 200,
-  val saveIntervalMs: Long = 5000,
-  val bufferSize: Int = 8192,
+  val saveIntervalMs: Long = 5_000,
+  val bufferSize: Int = 8 * 1024,
   val speedLimit: SpeedLimit = SpeedLimit.Unlimited,
-  val maxConcurrentDownloads: Int = 2,
+  val maxConcurrentDownloads: Int = 4,
   val maxConnectionsPerDownload: Int = 4,
-  val maxConnectionsPerHost: Int = 8,
+  val maxConnectionsPerHost: Int = 16,
 ) {
   init {
     require(retryCount >= 0) { "retryCount must be non-negative" }
@@ -66,6 +69,7 @@ data class DownloadConfig(
   }
 
   companion object {
-    val Default = DownloadConfig()
+    /** Default settings shared by the engine and its clients. */
+    val Default: DownloadConfig = DownloadConfig()
   }
 }