Added functioning read for Win32

src/socket.c

@@ -663,6 +663,86 @@ mrb_win32_basicsocket_close(mrb_state *mrb, mrb_value self)
   return mrb_nil_value();
 }
 
+static mrb_value
+mrb_win32_basicsocket_read(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));
+    return mrb_nil_value();
+  }
+
+  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;
+      } else {
+        mrb_str_cat(mrb, str, buf, n);
+        bytes_read += n;
+        if (bytes_read >= read_len)
+          keep_reading = 0;
+      }
+    }
+  }
+  /* 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);
+      }
+    }
+  }
+
+  return str;
+#undef BUF_LEN
+}
+
 static mrb_value
 mrb_win32_basicsocket_write(mrb_state *mrb, mrb_value self)
 {
@@ -762,6 +842,7 @@ 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));
 #endif