Add configurable limit for the maximum number of bytes/chars of content to parse before failing

[cowtowncoder]

(note: part of #637)

Jackson 2.15 included a few processing limits that can be applied to limit processing for "too big content"; first focusing on general nesting depth and max. length of individual tokens.
While this is good first step, it also makes sense to offer a simple way to limit maximum content in total allowed to be read -- typically a maximum document size, but in case of line-delimited input, maximum streaming content.

The reasoning for addition of such feature is that although users can -- if they must -- implement this at yet lower level (length-limited InputStream, for example), there are some benefits from Jackson streaming component offering this:

1. Less work for user (obviously), better accessibility leading to wider adoption and helping against possible DoS vectors
2. Better integration via well-defined exception type common to constraints violations (StreamConstraintsException)
3. More reliable limits when shared implementation used (i.e. less like users/devs implement faulty limits checks)

Note, too, that this feature significantly improves usefulness (or right now, lack thereof) of #863 to combine per-token limits with overall limits.

NOTE: the default setting for this limits should, however, be left as "unlimited": using anything else is likely to break some processing somewhere.
Limit has to be defined as 64-bit long (not int); default value to use then is likely Long.MAX_VALUE.

[pjfanning]

I guess built-in support would be good - but this limit is straightforward for users to apply themselves without waiting for a jackson solution.

If your input data is the form of

• InputStream - try SizeLimitInputStream or equivalent
• Reader - try SizeLimitReader or equivalent
• String - just check length() of String
• ByteBuffer - jackson-databind has ByteBufferBackedInputStream - you can write the ByteBuffer with this and then wrap the InputStream with the SizeLimitInputStream above
  • it may also be feasible to check the ByteBuffer capacity before reading from it

[cowtowncoder]

Still hoping to get this in 2.16 as it would be the last processing limit formally requested. But we'll see :)

[cowtowncoder]

Implemented for JSON backend (InputStream, Reader, non-blocking/async).