pg: Adventures in writing a new postgresql client

c/pgconn.c

@@ -0,0 +1,47 @@
+typedef struct PGconn PGconn;
+
+#define PG_FUNCS \
+    X(PQconnectdb, PGconn *, const char *) \
+    X(PQerrorMessage, char *, const PGconn *) \
+    X(PQfinish, void, PGconn *) \
+    X(PQlibVersion, int, void) \
+    X(PQserverVersion, int, const PGconn *) \
+    X(PQstatus, int, const PGconn *)
+
+#define X(n, r, ...) static r (*n)(__VA_ARGS__);
+PG_FUNCS
+#undef X
+
+static void fupg_load() {
+    void *handle = dlopen("libpq.so", RTLD_LAZY);
+    if (!handle) croak("Unable to load libpq: %s", dlerror());
+#define X(n, ...) if (!(n = dlsym(handle, #n))) croak("Unable to load libpq: %s", dlerror());
+PG_FUNCS
+#undef X
+}
+
+#undef PG_FUNCS
+
+
+typedef struct {
+    PGconn *conn;
+} fupg_conn;
+
+fupg_conn *fupg_connect(pTHX_ const char *str) {
+    SV *sv;
+    PGconn *conn = PQconnectdb(str);
+    if (PQstatus(conn) != 0) {
+        sv = newSVpvf("FU::PG connection error: %s", PQerrorMessage(conn));
+        PQfinish(conn);
+        croak_sv(sv);
+    }
+
+    fupg_conn *c = safecalloc(1, sizeof(fupg_conn));
+    c->conn = conn;
+    return c;
+}
+
+static void fupg_destroy(fupg_conn *c) {
+    PQfinish(c->conn);
+    safefree(c);
+}