feat(android): T-AND-005/006 WebSocket 推流 + 主机发现

2026-09-14 20:40:16 +08:00
parent 30c316a1cc
commit d27845ef43
2 changed files with 444 additions and 0 deletions
@@ -0,0 +1,116 @@
+package com.opendance.studio.net
+
+import android.util.Log
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.async
+import kotlinx.coroutines.awaitAll
+import kotlinx.coroutines.coroutineScope
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.flow.flowOn
+import kotlinx.coroutines.sync.Semaphore
+import kotlinx.coroutines.sync.withPermit
+import kotlinx.coroutines.withContext
+import java.net.Inet4Address
+import java.net.InetSocketAddress
+import java.net.NetworkInterface
+import java.net.Socket
+
+/**
+ * T-AND-006：主机发现
+ *
+ * Windows 客户端是**裸 WebSocket 服务端**（不是 HTTP 服务），因此不能靠扫描
+ * HTTP 端点发现；这里用「TCP 能否连上 8765 端口」作为探测手段。
+ *
+ * 策略：取手机在 WiFi 网的 IPv4 地址，推导 /24 网段，并发探测该网段内所有
+ * 主机的目标端口（默认并发 32、单机超时 300ms，整段约 2~3 秒）。
+ */
+object HostDiscovery {
+
+    private const val TAG = "HostDiscovery"
+    const val DEFAULT_PORT = 8765
+    private const val CONNECT_TIMEOUT_MS = 300
+    private const val MAX_CONCURRENCY = 32
+
+    /** 发现结果 */
+    data class Candidate(val ip: String, val port: Int, val latencyMs: Long)
+
+    /** 手机自身的 WiFi IPv4 地址（形如 192.168.1.23），无网络时返回 null */
+    suspend fun localIpv4Address(): String? = withContext(Dispatchers.IO) {
+        try {
+            val candidates = mutableListOf<String>()
+            for (nif in NetworkInterface.getNetworkInterfaces()) {
+                if (!nif.isUp || nif.isLoopback) continue
+                val name = nif.name.lowercase()
+                // 排除蜂窝与隧道网卡，优先 WiFi / 以太网
+                if (name.startsWith("rmnet") || name.startsWith("dummy") || name.startsWith("tun")) continue
+
+                for (address in nif.inetAddresses) {
+                    if (address !is Inet4Address || address.isLoopbackAddress) continue
+                    val ip = address.hostAddress ?: continue
+                    // 排除链路本地地址（169.254.x.x）
+                    if (ip.startsWith("169.254.")) continue
+                    candidates.add(ip)
+                }
+            }
+            // 优先返回私有网段地址；否则退回第一个可用地址
+            candidates.firstOrNull { isPrivateIpv4(it) } ?: candidates.firstOrNull()
+        } catch (e: Exception) {
+            Log.w(TAG, "获取本机地址失败：${e.message}")
+            null
+        }
+    }
+
+    /** 判断是否为 RFC1918 私有地址 */
+    fun isPrivateIpv4(ip: String): Boolean {
+        val parts = ip.split(".").mapNotNull { it.toIntOrNull() }
+        if (parts.size != 4) return false
+        val (a, b) = parts[0] to parts[1]
+        return a == 10 ||
+            (a == 172 && b in 16..31) ||
+            (a == 192 && b == 168)
+    }
+
+    /** 由本机地址推导 /24 前缀，如 192.168.1.23 → "192.168.1" */
+    fun subnetPrefix(ip: String): String? {
+        val parts = ip.split(".")
+        if (parts.size != 4) return null
+        return parts.take(3).joinToString(".")
+    }
+
+    /**
+     * 扫描网段。以 Flow 形式逐步产出候选，便于 UI 边扫边显示。
+     */
+    fun scan(prefix: String, port: Int = DEFAULT_PORT): Flow<Candidate> = flow {
+        val semaphore = Semaphore(MAX_CONCURRENCY)
+        val candidates = coroutineScope {
+            (1..254).map { last ->
+                async(Dispatchers.IO) {
+                    semaphore.withPermit {
+                        probe("$prefix.$last", port)
+                    }
+                }
+            }.awaitAll()
+        }
+        // 按延迟排序，最快响应的最可能是目标机
+        candidates.filterNotNull().sortedBy { it.latencyMs }.forEach { emit(it) }
+    }.flowOn(Dispatchers.IO)
+
+    /** 探测单个主机：能建立 TCP 连接即认为端口开放 */
+    private fun probe(ip: String, port: Int): Candidate? {
+        val started = System.currentTimeMillis()
+        return try {
+            Socket().use { socket ->
+                socket.connect(InetSocketAddress(ip, port), CONNECT_TIMEOUT_MS)
+                Candidate(ip, port, System.currentTimeMillis() - started)
+            }
+        } catch (e: Exception) {
+            null
+        }
+    }
+
+    /** 单个主机连通性检查（连接页「测试连接」用） */
+    suspend fun checkHost(ip: String, port: Int = DEFAULT_PORT): Candidate? = withContext(Dispatchers.IO) {
+        probe(ip, port)
+    }
+}