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Add generic Base.unsafe_read using try_strides #16

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Add generic Base.unsafe_read using try_strides #16

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7000501
Add generic Base.unsafe_read using has_strided_get
nhz2 Feb 2, 2026
0cb911a
switch to try_strides
nhz2 May 19, 2026
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73 changes: 46 additions & 27 deletions src/InputBuffers.jl
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Original file line number Diff line number Diff line change
Expand Up @@ -90,33 +90,52 @@ function Base.readbytes!(b::InputBuffer, out::AbstractArray{UInt8}, nb=length(ou
end
Base.readavailable(b::InputBuffer) = read(b)

const ByteVector = Union{
Vector{UInt8},
Base.CodeUnits{UInt8, String},
typeof(view(codeunits("abc"), :)),
typeof(view(codeunits("abc"), 1:2)),
typeof(view(zeros(UInt8, 3), :)),
typeof(view(zeros(UInt8, 3), 1:2))
}

# Using @noinline to hopefully prevent strange TBAA issues based on where p comes from
@noinline function Base.unsafe_read(b::InputBuffer, p::Ptr{UInt8}, n::UInt)::Nothing
nb::Int64 = min(n, bytesavailable(b))
temp = Vector{UInt8}(undef, nb)
copyto!(temp, Int64(1), b.data, Int64(b.pos+firstindex(b.data)), nb)
cconv_temp = Base.cconvert(Ptr{UInt8}, temp)
GC.@preserve cconv_temp unsafe_copyto!(p, Base.unsafe_convert(Ptr{UInt8}, cconv_temp), nb)
b.pos += nb
nb < n && throw(EOFError())
nothing
end
@noinline function Base.unsafe_read(b::InputBuffer{<:ByteVector}, p::Ptr{UInt8}, n::UInt)::Nothing
nb::Int64 = min(n, bytesavailable(b))
cconv_data = Base.cconvert(Ptr{UInt8}, b.data)
GC.@preserve cconv_data unsafe_copyto!(p, Base.unsafe_convert(Ptr{UInt8}, cconv_data) + b.pos, nb)
b.pos += nb
nb < n && throw(EOFError())
nothing
@static if isdefined(Base, :try_strides)
# Using @noinline to hopefully prevent strange TBAA issues based on where p comes from
@noinline function Base.unsafe_read(b::InputBuffer, p::Ptr{UInt8}, n::UInt)::Nothing
nb::Int64 = min(n, bytesavailable(b))
if is_ptr_loadable(b.data) && try_strides(b.data) === (1,) && isone(Base.elsize(b.data))
cconv_data = Base.cconvert(Ptr{UInt8}, b.data)
GC.@preserve cconv_data unsafe_copyto!(p, Base.unsafe_convert(Ptr{UInt8}, cconv_data) + b.pos, nb)
else
temp = Vector{UInt8}(undef, nb)
copyto!(temp, Int64(1), b.data, Int64(b.pos+firstindex(b.data)), nb)
cconv_temp = Base.cconvert(Ptr{UInt8}, temp)
GC.@preserve cconv_temp unsafe_copyto!(p, Base.unsafe_convert(Ptr{UInt8}, cconv_temp), nb)
end
b.pos += nb
nb < n && throw(EOFError())
nothing
end
else
const ByteVector = Union{
Vector{UInt8},
Base.CodeUnits{UInt8, String},
typeof(view(codeunits("abc"), :)),
typeof(view(codeunits("abc"), 1:2)),
typeof(view(zeros(UInt8, 3), :)),
typeof(view(zeros(UInt8, 3), 1:2))
}

# Using @noinline to hopefully prevent strange TBAA issues based on where p comes from
@noinline function Base.unsafe_read(b::InputBuffer, p::Ptr{UInt8}, n::UInt)::Nothing
nb::Int64 = min(n, bytesavailable(b))
temp = Vector{UInt8}(undef, nb)
copyto!(temp, Int64(1), b.data, Int64(b.pos+firstindex(b.data)), nb)
cconv_temp = Base.cconvert(Ptr{UInt8}, temp)
GC.@preserve cconv_temp unsafe_copyto!(p, Base.unsafe_convert(Ptr{UInt8}, cconv_temp), nb)
b.pos += nb
nb < n && throw(EOFError())
nothing
end
@noinline function Base.unsafe_read(b::InputBuffer{<:ByteVector}, p::Ptr{UInt8}, n::UInt)::Nothing
nb::Int64 = min(n, bytesavailable(b))
cconv_data = Base.cconvert(Ptr{UInt8}, b.data)
GC.@preserve cconv_data unsafe_copyto!(p, Base.unsafe_convert(Ptr{UInt8}, cconv_data) + b.pos, nb)
b.pos += nb
nb < n && throw(EOFError())
nothing
end
end

# TODO Benchmark to see if the following are worth implementing
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