Add RPC API

src/rpc.c

@@ -0,0 +1,92 @@
+#include "rpc.h"
+
+struct mg_rpc {
+  struct mg_rpc *next;
+  struct mg_str method;
+  void (*fn)(struct mg_rpc_req *);
+  void *fn_data;
+};
+
+void mg_rpc_add(void **head, struct mg_str method,
+                void (*fn)(struct mg_rpc_req *), void *fn_data) {
+  struct mg_rpc *rpc = (struct mg_rpc *) calloc(1, sizeof(*rpc));
+  rpc->method = mg_strdup(method), rpc->fn = fn, rpc->fn_data = fn_data;
+  rpc->next = (struct mg_rpc *) *head, *head = rpc;
+}
+
+void mg_rpc_free(void **head) {
+  while (head != NULL && *head != NULL) {
+    struct mg_rpc *rpc = *(struct mg_rpc **) head;
+    *head = rpc->next;
+    free((void *) rpc->method.ptr);
+    free(rpc);
+  }
+}
+
+void mg_rpc_process(void **head, struct mg_str s, mg_pfn_t pfn, void *pfnd) {
+  struct mg_rpc_req req = {{s.ptr, s.len}, pfn, pfnd, NULL};
+  int len, off = mg_json_get(s.ptr, (int) s.len, "$.method", &len);
+  if (off > 0 && s.ptr[off] == '"') {
+    struct mg_str m = mg_str_n(&s.ptr[off + 1], (size_t) len - 2);
+    struct mg_rpc *h = *(struct mg_rpc **) head;
+    while (h != NULL && !mg_match(m, h->method, NULL)) h = h->next;
+    if (h != NULL) {
+      req.fn_data = h->fn_data;
+      h->fn(&req);
+    } else {
+      mg_rpc_err(&req, -32601, "\"%.*s not found\"", (int) m.len, m.ptr);
+    }
+  } else {
+    mg_rpc_err(&req, -32700, "%.*Q", (int) s.len, s.ptr);
+  }
+}
+
+void mg_rpc_vok(struct mg_rpc_req *r, const char *fmt, va_list *ap) {
+  int len, off = mg_json_get(r->frame.ptr, (int) r->frame.len, "$.id", &len);
+  if (off > 0) {
+    mg_rprintf(r->pfn, r->pfn_data, "{%Q:%.*s,%Q:", "id", len,
+               &r->frame.ptr[off], "result");
+    mg_vrprintf(r->pfn, r->pfn_data, fmt == NULL ? "null" : fmt, ap);
+    mg_rprintf(r->pfn, r->pfn_data, "}");
+  }
+}
+
+void mg_rpc_ok(struct mg_rpc_req *r, const char *fmt, ...) {
+  va_list ap;
+  va_start(ap, fmt);
+  mg_rpc_vok(r, fmt, &ap);
+  va_end(ap);
+}
+
+void mg_rpc_verr(struct mg_rpc_req *r, int code, const char *fmt, va_list *ap) {
+  int len, off = mg_json_get(r->frame.ptr, (int) r->frame.len, "$.id", &len);
+  mg_rprintf(r->pfn, r->pfn_data, "{");
+  if (off > 0) {
+    mg_rprintf(r->pfn, r->pfn_data, "%Q:%.*s,", "id", len, &r->frame.ptr[off]);
+  }
+  mg_rprintf(r->pfn, r->pfn_data, "%Q:{%Q:%d,%Q:", "error", "code", code,
+             "message");
+  mg_vrprintf(r->pfn, r->pfn_data, fmt == NULL ? "null" : fmt, ap);
+  mg_rprintf(r->pfn, r->pfn_data, "}}");
+}
+
+void mg_rpc_err(struct mg_rpc_req *r, int code, const char *fmt, ...) {
+  va_list ap;
+  va_start(ap, fmt);
+  mg_rpc_verr(r, code, fmt, &ap);
+  va_end(ap);
+}
+
+static size_t print_methods(mg_pfn_t pfn, void *pfn_data, va_list *ap) {
+  struct mg_rpc *h, **head = (struct mg_rpc **) va_arg(*ap, void **);
+  size_t len = 0;
+  for (h = *head; h != NULL; h = h->next) {
+    len += mg_rprintf(pfn, pfn_data, "%s%.*Q", h == *head ? "" : ",",
+                      (int) h->method.len, h->method.ptr);
+  }
+  return len;
+}
+
+void mg_rpc_list(struct mg_rpc_req *r) {
+  mg_rpc_ok(r, "[%M]", print_methods, r->fn_data);
+}