WIP LSP client

This contains the start of an LSP client.
Nothing (except starting the LSP server) works
at the moment and the feature is disabled by default.

1 files changed, 163 insertions, 0 deletions

diff --git a/src/dged/lsp.c b/src/dged/lsp.c
new file mode 100644
index 0000000..3c699f4
--- /dev/null
+++ b/src/dged/lsp.c
@@ -0,0 +1,163 @@
+#include "lsp.h"
+
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "buffer.h"
+#include "process.h"
+#include "reactor.h"
+
+struct lsp {
+  const char *name;
+  char *const *command;
+  struct process *process;
+  struct reactor *reactor;
+  struct buffer *stderr_buffer;
+  struct lsp_client client_impl;
+  uint32_t stdin_event;
+  uint32_t stdout_event;
+  uint32_t stderr_event;
+};
+
+struct lsp *lsp_create(char *const command[], struct reactor *reactor,
+                       struct buffer *stderr_buffer,
+                       struct lsp_client client_impl, const char *name) {
+  // check length of command
+  if (command == NULL) {
+    return NULL;
+  }
+
+  uint32_t command_len = 0;
+  while (command[command_len] != NULL) {
+    ++command_len;
+  }
+
+  if (command_len == 0) {
+    return NULL;
+  }
+
+  struct lsp *lsp = calloc(1, sizeof(struct lsp));
+
+  char **cmd = calloc(command_len + 1, sizeof(const char *));
+  memcpy(cmd, command, sizeof(const char *) * command_len);
+  cmd[command_len] = NULL;
+  lsp->command = cmd;
+
+  if (name != NULL) {
+    lsp->name = strdup(name);
+  } else {
+#ifdef __unix__
+    const char *lslash = strrchr(lsp->command[0], '/');
+#elif defined(_WIN32) || defined(WIN32)
+    const char *lslash = strrchr(lsp->command[0], '\\');
+#endif
+    if (lslash == NULL) {
+      lsp->name = strdup(lsp->command[0]);
+    } else {
+      lsp->name = strdup(lslash + 1);
+    }
+  }
+  lsp->stderr_buffer = stderr_buffer;
+  lsp->client_impl = client_impl;
+  lsp->reactor = reactor;
+  lsp->stdin_event = -1;
+  lsp->stdout_event = -1;
+  lsp->stderr_event = -1;
+
+  return lsp;
+}
+
+void lsp_destroy(struct lsp *lsp) {
+  free((void *)lsp->name);
+  if (lsp->process != NULL) {
+    free(lsp->process);
+  }
+  if (lsp->command != NULL) {
+    char *command = lsp->command[0];
+    while (command != NULL) {
+      free(command);
+      ++command;
+    }
+
+    free((void *)lsp->command);
+  }
+  free(lsp);
+}
+
+uint32_t lsp_update(struct lsp *lsp, struct lsp_response **responses,
+                    uint32_t responses_capacity) {
+
+  (void)responses;
+  (void)responses_capacity;
+
+  if (!lsp_server_running(lsp)) {
+    return -1;
+  }
+
+  // read stderr
+  if (lsp->stderr_event != (uint32_t)-1) {
+    uint8_t buf[1024];
+    if (reactor_poll_event(lsp->reactor, lsp->stderr_event)) {
+      ssize_t nb = 0;
+      while ((nb = read(lsp->process->stderr, buf, 1024)) > 0) {
+        buffer_set_readonly(lsp->stderr_buffer, false);
+        buffer_add(lsp->stderr_buffer, buffer_end(lsp->stderr_buffer), buf, nb);
+        buffer_set_readonly(lsp->stderr_buffer, true);
+      }
+    }
+  }
+
+  return 0;
+}
+
+int lsp_start_server(struct lsp *lsp) {
+  struct process p;
+  struct process_create_result res = process_create(lsp->command, &p);
+
+  if (!res.ok) {
+    // TODO: losing error message here
+    return -1;
+  }
+
+  lsp->process = calloc(1, sizeof(struct process));
+  memcpy(lsp->process, &p, sizeof(struct process));
+  lsp->stderr_event = reactor_register_interest(
+      lsp->reactor, lsp->process->stderr, ReadInterest);
+
+  return 0;
+}
+
+int lsp_restart_server(struct lsp *lsp) {
+  if (lsp_server_running(lsp)) {
+    lsp_stop_server(lsp);
+  }
+
+  return lsp_start_server(lsp);
+}
+
+void lsp_stop_server(struct lsp *lsp) {
+  process_kill(lsp->process);
+  process_destroy(lsp->process);
+  free(lsp->process);
+  lsp->process = NULL;
+}
+
+bool lsp_server_running(const struct lsp *lsp) {
+  if (lsp->process == NULL) {
+    return false;
+  }
+
+  return process_running(lsp->process);
+}
+
+uint64_t lsp_server_pid(const struct lsp *lsp) {
+  if (!lsp_server_running(lsp)) {
+    return -1;
+  }
+
+  return lsp->process->id;
+}
+
+const char *lsp_server_name(const struct lsp *lsp) { return lsp->name; }