Changed IO overrides to use sysread and syswrite instead of read and write

src/socket.c

@@ -663,88 +663,59 @@ mrb_win32_basicsocket_close(mrb_state *mrb, mrb_value self)
   return mrb_nil_value();
 }
 
+#define E_EOF_ERROR                (mrb_class_get(mrb, "EOFError"))
 static mrb_value
-mrb_win32_basicsocket_read(mrb_state *mrb, mrb_value self)
+mrb_win32_basicsocket_sysread(mrb_state *mrb, mrb_value self)
 {
-#define BUF_LEN 4096
-  char buf[BUF_LEN];
-  int sd, bytes_read;
-  mrb_int read_len;
-  mrb_value str = mrb_str_new(mrb, NULL, 0);
-  mrb_value len_arg = mrb_nil_value();
-
-  /* For compatibility with IO::read, we accept an object instead of just
-   * an mrb_int. Then we raise an exception if it isn't an mrb_int or nil.
-   */
-  mrb_get_args(mrb, "|o", &len_arg);
-  if (mrb_fixnum_p(len_arg)) {
-    read_len = mrb_fixnum(len_arg);
-    if (read_len < 0) {
-      mrb_str_cat_cstr(mrb, str, "negative length: ");
-      mrb_str_append(mrb, str, len_arg);
-      mrb_str_cat_cstr(mrb, str, " given");
-      mrb_raise(mrb, E_ARGUMENT_ERROR, mrb_string_value_cstr(mrb, &str));
-      return mrb_nil_value();
-    } else if (read_len == 0) {
-      return str;
-    }
-  } else if (mrb_nil_p(len_arg)) {
-    read_len = 0;
-  } else {
-    mrb_str_cat_cstr(mrb, str, "can't convert ");
-    mrb_str_append(mrb, str, len_arg);
-    mrb_str_cat_cstr(mrb, str, " into Integer");
-    mrb_raise(mrb, E_TYPE_ERROR, mrb_string_value_cstr(mrb, &str));
+  int sd, ret;
+  mrb_value buf = mrb_nil_value();
+  mrb_int maxlen;
+
+  mrb_get_args(mrb, "i|S", &maxlen, &buf);
+  if (maxlen < 0) {
     return mrb_nil_value();
   }
 
+  if (mrb_nil_p(buf)) {
+    buf = mrb_str_new(mrb, NULL, maxlen);
+  }
+  if (RSTRING_LEN(buf) != maxlen) {
+    buf = mrb_str_resize(mrb, buf, maxlen);
+  }
+
   sd = socket_fd(mrb, self);
-  bytes_read = 0;
-
-  /* Behavior of positive integer argument: read until length bytes have been
-   * read, or until the socket has closed. */
-  if (read_len > 0) {
-    int n = 0;
-    int max_read_len = BUF_LEN;
-    int keep_reading = 1;
-    while (keep_reading) {
-      if (max_read_len > (read_len - bytes_read))
-        max_read_len = read_len - bytes_read;
-      n = recv(sd, buf, max_read_len, 0);
-
-      if (n == SOCKET_ERROR) {
-        mrb_sys_fail(mrb, "recv");
-      } else if (n == 0) {
-        keep_reading = 0;
+  ret = recv(sd, RSTRING_PTR(buf), maxlen, 0);
+
+  switch (ret) {
+    case 0: /* EOF */
+      if (maxlen == 0) {
+        buf = mrb_str_new_cstr(mrb, "");
       } else {
-        mrb_str_cat(mrb, str, buf, n);
-        bytes_read += n;
-        if (bytes_read >= read_len)
-          keep_reading = 0;
+        mrb_raise(mrb, E_EOF_ERROR, "sysread failed: End of File");
       }
-    }
-  }
-  /* Behavior of nil/default argument: read until socket has closed */
-  else {
-    int keep_reading = 1;
-    while (keep_reading) {
-      bytes_read = recv(sd, buf, BUF_LEN, 0);
-      if (bytes_read == SOCKET_ERROR) {
-        mrb_sys_fail(mrb, "recv");
-      } else if (bytes_read == 0) {
-        keep_reading = 0;
-      } else {
-        mrb_str_cat(mrb, str, buf, bytes_read);
+      break;
+    case SOCKET_ERROR: /* Error */
+      mrb_sys_fail(mrb, "recv");
+      break;
+    default:
+      if (RSTRING_LEN(buf) != ret) {
+        buf = mrb_str_resize(mrb, buf, ret);
       }
-    }
+      break;
   }
 
-  return str;
-#undef BUF_LEN
+  return buf;
+}
+
+static mrb_value
+mrb_win32_basicsocket_sysseek(mrb_state *mrb, mrb_value self)
+{
+  mrb_raise(mrb, E_NOTIMP_ERROR, "sysseek not implemented for windows sockets");
+  return mrb_nil_value();
 }
 
 static mrb_value
-mrb_win32_basicsocket_write(mrb_state *mrb, mrb_value self)
+mrb_win32_basicsocket_syswrite(mrb_state *mrb, mrb_value self)
 {
   int n;
   SOCKET sd;
@@ -842,8 +813,9 @@ mrb_mruby_socket_gem_init(mrb_state* mrb)
   /* Windows IO Method Overrides on BasicSocket */
 #ifdef _WIN32
   mrb_define_method(mrb, bsock, "close", mrb_win32_basicsocket_close, MRB_ARGS_NONE());
-  mrb_define_method(mrb, bsock, "read",  mrb_win32_basicsocket_read,  MRB_ARGS_OPT(1));
-  mrb_define_method(mrb, bsock, "write", mrb_win32_basicsocket_write, MRB_ARGS_REQ(1));
+  mrb_define_method(mrb, bsock, "sysread", mrb_win32_basicsocket_sysread, MRB_ARGS_REQ(1)|MRB_ARGS_OPT(1));
+  mrb_define_method(mrb, bsock, "sysseek", mrb_win32_basicsocket_sysseek, MRB_ARGS_REQ(1));
+  mrb_define_method(mrb, bsock, "syswrite", mrb_win32_basicsocket_syswrite, MRB_ARGS_REQ(1));
 #endif
 
   constants = mrb_define_module_under(mrb, sock, "Constants");