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response/result.rs: Replace generate_deser_type macro with a function
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This macro is unnecessary, function is enough here.
For ease of future development, lets get rid of such macros.
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@Lorak-mmk
Lorak-mmk committed Oct 28, 2024
1 parent 0e0b754 commit 6172124
Showing 1 changed file with 96 additions and 91 deletions.
187 changes: 96 additions & 91 deletions scylla-cql/src/frame/response/result.rs
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Original file line number Diff line number Diff line change
@@ -1,8 +1,8 @@
use crate::cql_to_rust::{FromRow, FromRowError};
use crate::frame::frame_errors::{
ColumnSpecParseError, ColumnSpecParseErrorKind, CqlResultParseError, CqlTypeParseError,
PreparedParseError, ResultMetadataParseError, RowsParseError, SchemaChangeEventParseError,
SetKeyspaceParseError, TableSpecParseError,
LowLevelDeserializationError, PreparedParseError, ResultMetadataParseError, RowsParseError,
SchemaChangeEventParseError, SetKeyspaceParseError, TableSpecParseError,
};
use crate::frame::request::query::PagingStateResponse;
use crate::frame::response::event::SchemaChangeEvent;
Expand Down Expand Up @@ -603,99 +603,104 @@ pub enum Result {
SchemaChange(SchemaChange),
}

macro_rules! generate_deser_type {
($deser_type: ident, $l: lifetime, $read_string: expr) => {
fn $deser_type<'frame>(
buf: &mut &'frame [u8],
) -> StdResult<ColumnType<$l>, CqlTypeParseError> {
use ColumnType::*;
let id = types::read_short(buf)
.map_err(|err| CqlTypeParseError::TypeIdParseError(err.into()))?;
Ok(match id {
0x0000 => {
// We use types::read_string instead of $read_string here on purpose.
// Chances are the underlying string is `...DurationType`, in which case
// we don't need to allocate it at all. Only for Custom types
// (which we don't support anyway) do we need to allocate.
// OTOH, the macro argument function deserializes borrowed OR owned string;
// here we want to always deserialize borrowed string.
let type_str = types::read_string(buf)
.map_err(CqlTypeParseError::CustomTypeNameParseError)?;
match type_str {
"org.apache.cassandra.db.marshal.DurationType" => Duration,
_ => Custom(type_str.to_owned().into()),
}
}
0x0001 => Ascii,
0x0002 => BigInt,
0x0003 => Blob,
0x0004 => Boolean,
0x0005 => Counter,
0x0006 => Decimal,
0x0007 => Double,
0x0008 => Float,
0x0009 => Int,
0x000B => Timestamp,
0x000C => Uuid,
0x000D => Text,
0x000E => Varint,
0x000F => Timeuuid,
0x0010 => Inet,
0x0011 => Date,
0x0012 => Time,
0x0013 => SmallInt,
0x0014 => TinyInt,
0x0015 => Duration,
0x0020 => List(Box::new($deser_type(buf)?)),
0x0021 => Map(Box::new($deser_type(buf)?), Box::new($deser_type(buf)?)),
0x0022 => Set(Box::new($deser_type(buf)?)),
0x0030 => {
let keyspace_name =
$read_string(buf).map_err(CqlTypeParseError::UdtKeyspaceNameParseError)?;
let type_name =
$read_string(buf).map_err(CqlTypeParseError::UdtNameParseError)?;
let fields_size: usize = types::read_short(buf)
.map_err(|err| CqlTypeParseError::UdtFieldsCountParseError(err.into()))?
.into();

let mut field_types: Vec<(Cow<$l, str>, ColumnType)> =
Vec::with_capacity(fields_size);

for _ in 0..fields_size {
let field_name =
$read_string(buf).map_err(CqlTypeParseError::UdtFieldNameParseError)?;
let field_type = $deser_type(buf)?;

field_types.push((field_name.into(), field_type));
}

UserDefinedType {
type_name: type_name.into(),
keyspace: keyspace_name.into(),
field_types,
}
}
0x0031 => {
let len: usize = types::read_short(buf)
.map_err(|err| CqlTypeParseError::TupleLengthParseError(err.into()))?
.into();
let mut types = Vec::with_capacity(len);
for _ in 0..len {
types.push($deser_type(buf)?);
}
Tuple(types)
}
id => {
return Err(CqlTypeParseError::TypeNotImplemented(id));
}
})
fn deser_type_generic<'frame, 'result, StrT: Into<Cow<'result, str>>>(
buf: &mut &'frame [u8],
read_string: fn(&mut &'frame [u8]) -> StdResult<StrT, LowLevelDeserializationError>,
) -> StdResult<ColumnType<'result>, CqlTypeParseError> {
use ColumnType::*;
let id =
types::read_short(buf).map_err(|err| CqlTypeParseError::TypeIdParseError(err.into()))?;
Ok(match id {
0x0000 => {
// We use types::read_string instead of read_string argument here on purpose.
// Chances are the underlying string is `...DurationType`, in which case
// we don't need to allocate it at all. Only for Custom types
// (which we don't support anyway) do we need to allocate.
// OTOH, the macro argument function deserializes borrowed OR owned string;
// here we want to always deserialize borrowed string.
let type_str =
types::read_string(buf).map_err(CqlTypeParseError::CustomTypeNameParseError)?;
match type_str {
"org.apache.cassandra.db.marshal.DurationType" => Duration,
_ => Custom(type_str.to_owned().into()),
}
}
};
0x0001 => Ascii,
0x0002 => BigInt,
0x0003 => Blob,
0x0004 => Boolean,
0x0005 => Counter,
0x0006 => Decimal,
0x0007 => Double,
0x0008 => Float,
0x0009 => Int,
0x000B => Timestamp,
0x000C => Uuid,
0x000D => Text,
0x000E => Varint,
0x000F => Timeuuid,
0x0010 => Inet,
0x0011 => Date,
0x0012 => Time,
0x0013 => SmallInt,
0x0014 => TinyInt,
0x0015 => Duration,
0x0020 => List(Box::new(deser_type_generic(buf, read_string)?)),
0x0021 => Map(
Box::new(deser_type_generic(buf, read_string)?),
Box::new(deser_type_generic(buf, read_string)?),
),
0x0022 => Set(Box::new(deser_type_generic(buf, read_string)?)),
0x0030 => {
let keyspace_name =
read_string(buf).map_err(CqlTypeParseError::UdtKeyspaceNameParseError)?;
let type_name = read_string(buf).map_err(CqlTypeParseError::UdtNameParseError)?;
let fields_size: usize = types::read_short(buf)
.map_err(|err| CqlTypeParseError::UdtFieldsCountParseError(err.into()))?
.into();

let mut field_types: Vec<(Cow<'result, str>, ColumnType)> =
Vec::with_capacity(fields_size);

for _ in 0..fields_size {
let field_name =
read_string(buf).map_err(CqlTypeParseError::UdtFieldNameParseError)?;
let field_type = deser_type_generic(buf, read_string)?;

field_types.push((field_name.into(), field_type));
}

UserDefinedType {
type_name: type_name.into(),
keyspace: keyspace_name.into(),
field_types,
}
}
0x0031 => {
let len: usize = types::read_short(buf)
.map_err(|err| CqlTypeParseError::TupleLengthParseError(err.into()))?
.into();
let mut types = Vec::with_capacity(len);
for _ in 0..len {
types.push(deser_type_generic(buf, read_string)?);
}
Tuple(types)
}
id => {
return Err(CqlTypeParseError::TypeNotImplemented(id));
}
})
}

generate_deser_type!(_deser_type_borrowed, 'frame, types::read_string);
fn _deser_type_borrowed<'frame>(
buf: &mut &'frame [u8],
) -> StdResult<ColumnType<'frame>, CqlTypeParseError> {
deser_type_generic(buf, |buf| types::read_string(buf))
}

generate_deser_type!(deser_type_owned, 'static, |buf| types::read_string(buf).map(ToOwned::to_owned));
fn deser_type_owned(buf: &mut &[u8]) -> StdResult<ColumnType<'static>, CqlTypeParseError> {
deser_type_generic(buf, |buf| types::read_string(buf).map(ToOwned::to_owned))
}

/// Deserializes a table spec, be it per-column one or a global one,
/// in the borrowed form.
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