Add WriteString

Bug: b/495556334

Author: Databean

base/cvd/cuttlefish/io/BUILD.bazel

@@ -372,6 +372,7 @@ cf_cc_library(
     hdrs = ["string.h"],
     deps = [
         "//cuttlefish/io",
+        "//cuttlefish/io:write_exact",
         "//cuttlefish/result:expect",
         "//cuttlefish/result:result_type",
     ],

base/cvd/cuttlefish/io/string.cc

@@ -21,6 +21,7 @@
 #include <string>
 
 #include "cuttlefish/io/io.h"
+#include "cuttlefish/io/write_exact.h"
 #include "cuttlefish/result/expect.h"
 #include "cuttlefish/result/result_type.h"
 
@@ -37,4 +38,9 @@ Result<std::string> ReadToString(Reader& reader, size_t buffer_size) {
   return out.str();
 }
 
+Result<void> WriteString(Writer& writer, std::string_view str) {
+  CF_EXPECT(WriteExact(writer, str.data(), str.size()));
+  return {};
+}
+
 }  // namespace cuttlefish

base/cvd/cuttlefish/io/string.h

@@ -15,15 +15,17 @@
 
 #pragma once
 
-#include <stdint.h>
+#include <stddef.h>
 
 #include <string>
+#include <string_view>
 
 #include "cuttlefish/io/io.h"
 #include "cuttlefish/result/result_type.h"
 
 namespace cuttlefish {
 
 Result<std::string> ReadToString(Reader&, size_t buffer_size = 1 << 16);
+Result<void> WriteString(Writer&, std::string_view);
 
 }  // namespace cuttlefish