Repository navigation
Conversation
A schema of Z fields, fixed-length S or H fields of length 0, or nested objects and arrays of those, describes records of no bytes, so the count is bounded by nothing in the data: a few bytes can declare any number of records. This is the zero-length-marker problem that the optimized type header already excludes T, F, Z and N for. Require a record's fields to total at least one byte, and a parser to reject a container whose schema does not, whatever its count.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
A schema made only of zero-length fields (
Z,S/Hof length 0, or nested objects/arrays of those) describes records of zero bytes, so nothing in the data bounds<count>: a few bytes can declare any number of records. For example,[${U\x01aZ}#Lfollowed by an 8-byte count is 18 bytes claiming 2^40 records, and a decoder that builds them runs effectively forever.This is the zero-length-marker problem (nlohmann/json#2793) that already excludes
T,F,ZandNfrom an optimized type header. This PR adds schema rule 8, under which a record's fields must total at least one byte, and a parser rejects a container whose schema doesn't, whatever its count. It also adds a sentence to the Optimized Format section pointing to the rule.Zfields beside fields that take bytes are unaffected. Implemented in cpp-serpent.