Byte Array Prefix Dispatch
Match caller-supplied byte prefixes and expose all longest ties; no protocol-identification guarantee.
Description
Match caller-supplied byte prefixes and expose all longest ties; no protocol-identification guarantee.
A dispatch table may contain several matching byte prefixes, including equal-length longest ties.
When to use this tool
Match caller-supplied byte prefixes and expose all longest ties; no protocol-identification guarantee.
- Prepare the supplied bytes, prefixesJson fields for this operation.
- Compare the complete example with the representation used by your own input before carrying the result into another step.
How to use the tool and how it works
- Enter bytes, prefixesJson. Use the exact text syntax, units and index conventions explained below.
- Run the tool. If input validation fails, correct the supplied fields before interpreting any result.
- Read result.matchingIndexes, result.longestIndexes. Interpret false, null and empty lists using the distinctions below; they can be valid outputs.
Parse prefixesJson as nonempty byte arrays. Return every prefix index matching the start of bytes, then retain all matches having maximum prefix length as longestIndexes.1
| Input field | Meaning and representation | Accepted input |
|---|---|---|
| bytes | bytes. | List of integers from 0 to 255; at most 128 bytes |
| prefixesJson | JSON text, entered as one text field. The decoded structure is illustrated below; it is not a separate file. | Text |
For the JSON text fields, the following decoded structures show the example records before they are serialized into input strings. Keep field names, list nesting and value types as shown.
[
{
"field": "prefixesJson",
"decoded": [
[
1
],
[
1,
2
],
[
2
]
]
}
]| Output field | Interpretation |
|---|---|
| result | Object containing the named outputs below. |
| result.matchingIndexes | The matching indexes list in the ordering and representation described above. |
| result.longestIndexes | The longest indexes list in the ordering and representation described above. |
{
"input": {
"bytes": [
1,
2,
3
],
"prefixesJson": "[[1],[1,2],[2]]"
},
"output": {
"result": {
"matchingIndexes": [
0,
1
],
"longestIndexes": [
1
]
}
}
}Limitations and assumptions
- No winner is chosen among equal longest prefixes. Empty prefix records are rejected and the source bytes are not consumed.
- Every declared top-level field is required and unexpected fields are rejected. Numeric inputs must be finite; ordinary text fields are bounded to 8,192 UTF-16 code units, with tighter operation-specific limits where stated.
- Lists are limited to 128 entries. JSON text must meet bounded size and depth checks, and numeric outputs beyond the safe finite magnitude are rejected. Exact large integers use decimal strings.
- Indexes are zero-based and spans have an exclusive end unless explicitly stated otherwise. A valid false, null or empty-list result is distinct from malformed input.
Alternative or Complementary methods
Retain the field-width, bit-index and byte-order conventions when combining operations. Slicing, escaping, permutation and alignment are separate transforms; none supplies a complete framing or cryptographic protocol.
References
Similar or alternative tools
- Byte Array Escaping Inverse
Explicit byte-stuffing inverse with escape followed by reserved byte XOR 0x20; escape and sentinel must differ.
- Byte Array Escaping Transform
Explicit byte-stuffing transform with escape followed by reserved byte XOR 0x20; escape and sentinel must differ.