[mammoth] Move port server operations to their own class.

lib/mammoth/src/port_server.cpp

@@ -0,0 +1,45 @@
+#include "mammoth/port_server.h"
+
+#include <zcall.h>
+
+glcr::ErrorOr<PortServer> PortServer::Create() {
+  z_cap_t port;
+  RET_ERR(ZPortCreate(&port));
+  return PortServer(port);
+}
+
+PortServer PortServer::AdoptCap(z_cap_t cap) { return PortServer(cap); }
+
+PortServer::PortServer(z_cap_t port_cap) : port_cap_(port_cap) {}
+
+glcr::ErrorCode PortServer::CreateClient(z_cap_t *new_port) {
+  // FIXME: Restrict permissions.
+  return ZCapDuplicate(port_cap_, new_port);
+}
+
+glcr::ErrorCode PortServer::RecvCap(uint64_t *num_bytes, char *msg,
+                                    uint64_t *cap) {
+  uint64_t caps = 1;
+  RET_ERR(ZPortRecv(port_cap_, num_bytes, reinterpret_cast<uint8_t *>(msg),
+                    &caps, cap));
+
+  if (caps != 1) {
+    return glcr::FAILED_PRECONDITION;
+  }
+  return glcr::OK;
+}
+
+z_err_t PortServer::PollForIntCap(uint64_t *msg, uint64_t *cap) {
+  uint64_t bytes = sizeof(uint64_t);
+  uint64_t caps = 1;
+  RET_ERR(ZPortPoll(port_cap_, &bytes, reinterpret_cast<uint8_t *>(msg), &caps,
+                    cap));
+
+  if (bytes != sizeof(uint64_t)) {
+    return glcr::FAILED_PRECONDITION;
+  }
+  if (caps != 1) {
+    return glcr::FAILED_PRECONDITION;
+  }
+  return glcr::OK;
+}