[
https://issues.apache.org/jira/browse/AVRO-1335?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16143358#comment-16143358
]
Thiruvalluvan M. G. commented on AVRO-1335:
-------------------------------------------
The pull request looks good. However a couple of minor issues:
* Line 565 of setw should use {{2 * sizeof(T)}}. For `sizeof` operator gives
the number of bytes for the given type but the width in hexadecimal is 2 per
byte.
* Style issues: `int_to_hex` could be renamed to `intToHex` to make it
consistent with the rest of the code in the file.
* The following code can be replaced with `memcpy`:
{code}
for (int j = 0; j < kByteStringSize; j++) {
s[i*kByteStringSize + j] = hex_string[j];
}
{code}
> C++ should support field default values
> ---------------------------------------
>
> Key: AVRO-1335
> URL: https://issues.apache.org/jira/browse/AVRO-1335
> Project: Avro
> Issue Type: Improvement
> Components: c++
> Affects Versions: 1.7.4
> Reporter: Bin Guo
> Attachments: AVRO-1335.patch
>
>
> We found that resolvingDecoder could not provide bidirectional compatibility
> between different version of schemas.
> Especially for records, for example:
> {code:title=First schema}
> {
> "type": "record",
> "name": "TestRecord",
> "fields": [
> {
> "name": "MyData",
> "type": {
> "type": "record",
> "name": "SubData",
> "fields": [
> {
> "name": "Version1",
> "type": "string"
> }
> ]
> }
> },
> {
> "name": "OtherData",
> "type": "string"
> }
> ]
> }
> {code}
> {code:title=Second schema}
> {
> "type": "record",
> "name": "TestRecord",
> "fields": [
> {
> "name": "MyData",
> "type": {
> "type": "record",
> "name": "SubData",
> "fields": [
> {
> "name": "Version1",
> "type": "string"
> },
> {
> "name": "Version2",
> "type": "string"
> }
> ]
> }
> },
> {
> "name": "OtherData",
> "type": "string"
> }
> ]
> }
> {code}
> Say, node A knows only the first schema and node B knows the second schema,
> and the second schema has more fields.
> Any data generated by node B can be resolved by first schema 'cause the
> additional field is marked as skipped.
> But data generated by node A can not be resolved by second schema and throws
> an exception *"Don't know how to handle excess fields for reader."*
> This is because data is resolved exactly according to the auto-generated
> codec_traits which trying to read the excess field.
> The problem is we just can not only ignore the excess field in record, since
> the data after the troublesome record also needs to be resolved.
> Actually this problem stucked us for a very long time.
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
