Poor performance for String serialization about gson HOT 1 OPEN

This suggestion sounds reasonable, but is this rather a theoretical issue, or something you identified as performance issue when using Gson?

I assume this change would mainly help when writing large strings at the beginning of the JSON data. In the other cases it would not change much:

• When writing small strings at the beginning using ensureCapacity might have similar effects as the implicit resizing by append
• Writing large strings later in the JSON data might not trigger any resizing for ensureCapacity since the buffer is already large enough
• The perfectly sized buffer shown in your "Reproduction steps" would probably only matter for top-level string values (and which don't require escaping); for non-top-level string values subsequent values or closing ] or } would still cause resizing

But I am not completely sure. It seems the main advantages with your proposed changes would be:

• less buffer resizing for large strings at the beginning of the JSON data
• potentially perfectly sized buffers for top-level string values

Would probably also make sense to check not only for StringWriter but also for com.google.gson.internal.Streams.AppendableWriter then, in case the user provided directly a StringBuilder or StringBuffer to Gson.toJson(Object, Appendable).

from gson.