From 2c35dab352780ea19c479cd024b88dda70d60d71 Mon Sep 17 00:00:00 2001
From: mtfishman <mfishman@flatironinstitute.org>
Date: Tue, 14 May 2024 16:04:55 -0400
Subject: [PATCH 1/4] Define resize

---
 src/array.jl  | 42 ++++++++++++++++++++++++++++++++++++++++++
 test/array.jl | 21 +++++++++++++++++++++
 2 files changed, 63 insertions(+)

diff --git a/src/array.jl b/src/array.jl
index f2fb1a60..0679e79a 100644
--- a/src/array.jl
+++ b/src/array.jl
@@ -478,3 +478,45 @@ function Base.unsafe_wrap(::Type{Array}, arr::oneArray{T,N,oneL0.SharedBuffer})
   ptr = reinterpret(Ptr{T}, pointer(arr))
   unsafe_wrap(Array, ptr, size(arr))
 end
+
+## resizing
+
+"""
+  resize!(a::oneVector, n::Integer)
+
+Resize `a` to contain `n` elements. If `n` is smaller than the current collection length,
+the first `n` elements will be retained. If `n` is larger, the new elements are not
+guaranteed to be initialized.
+"""
+function Base.resize!(a::oneVector{T}, n::Integer) where {T}
+    # TODO: add additional space to allow for quicker resizing
+    maxsize = n * sizeof(T)
+    bufsize = if isbitstype(T)
+        maxsize
+    else
+        # type tag array past the data
+        maxsize + n
+    end
+
+    # replace the data with a new one. this 'unshares' the array.
+    # as a result, we can safely support resizing unowned buffers.
+    ctx = context()
+    dev = device(a)
+    buf = allocate(buftype(a), ctx, dev, bufsize, Base.datatype_alignment(T))
+    ptr = ZePtr{T}(buf)
+    m = min(length(a), n)
+    if m > 0
+        unsafe_copyto!(device(a), ptr, pointer(a), m)
+    end
+    new_data = DataRef(buf) do buf
+        free(buf)
+    end
+    unsafe_free!(a)
+
+    a.data = new_data
+    a.dims = (n,)
+    a.maxsize = maxsize
+    a.offset = 0
+
+    a
+end
diff --git a/test/array.jl b/test/array.jl
index b6b47dab..73121f86 100644
--- a/test/array.jl
+++ b/test/array.jl
@@ -74,3 +74,24 @@ end
   e = c .+ d
   @test oneAPI.buftype(e) == oneL0.SharedBuffer
 end
+
+@testset "resizing" begin
+  a = oneArray([1,2,3])
+
+  resize!(a, 3)
+  @test length(a) == 3
+  @test Array(a) == [1,2,3]
+
+  resize!(a, 5)
+  @test length(a) == 5
+  @test Array(a)[1:3] == [1,2,3]
+
+  resize!(a, 2)
+  @test length(a) == 2
+  @test Array(a)[1:2] == [1,2]
+
+  b = oneArray{Int}(undef, 0)
+  @test length(b) == 0
+  resize!(b, 1)
+  @test length(b) == 1
+end

From 9f0c88c26f1838bce28ddd2843bb8d7de8181b00 Mon Sep 17 00:00:00 2001
From: mtfishman <mfishman@flatironinstitute.org>
Date: Tue, 14 May 2024 16:22:45 -0400
Subject: [PATCH 2/4] Try fixing pointer conversion

---
 src/array.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/array.jl b/src/array.jl
index 0679e79a..6c669793 100644
--- a/src/array.jl
+++ b/src/array.jl
@@ -503,7 +503,7 @@ function Base.resize!(a::oneVector{T}, n::Integer) where {T}
     ctx = context()
     dev = device(a)
     buf = allocate(buftype(a), ctx, dev, bufsize, Base.datatype_alignment(T))
-    ptr = ZePtr{T}(buf)
+    ptr = pointer(buf)
     m = min(length(a), n)
     if m > 0
         unsafe_copyto!(device(a), ptr, pointer(a), m)

From 6c43e8b6c80d7346f0163727c2b52d292865111f Mon Sep 17 00:00:00 2001
From: mtfishman <mfishman@flatironinstitute.org>
Date: Tue, 14 May 2024 16:28:32 -0400
Subject: [PATCH 3/4] Try fixing unsafe_copyto call

---
 src/array.jl | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/array.jl b/src/array.jl
index 6c669793..c0aa6e0f 100644
--- a/src/array.jl
+++ b/src/array.jl
@@ -500,13 +500,13 @@ function Base.resize!(a::oneVector{T}, n::Integer) where {T}
 
     # replace the data with a new one. this 'unshares' the array.
     # as a result, we can safely support resizing unowned buffers.
-    ctx = context()
+    ctx = context(a)
     dev = device(a)
     buf = allocate(buftype(a), ctx, dev, bufsize, Base.datatype_alignment(T))
     ptr = pointer(buf)
     m = min(length(a), n)
     if m > 0
-        unsafe_copyto!(device(a), ptr, pointer(a), m)
+        unsafe_copyto!(ctx, dev, ptr, pointer(a), m)
     end
     new_data = DataRef(buf) do buf
         free(buf)

From 4ee1d5c7048ae7b7d511b1ad1feca8b29d61fc36 Mon Sep 17 00:00:00 2001
From: mtfishman <mfishman@flatironinstitute.org>
Date: Tue, 14 May 2024 16:38:13 -0400
Subject: [PATCH 4/4] Try improving pointer conversion

---
 src/array.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/array.jl b/src/array.jl
index c0aa6e0f..f765d2b3 100644
--- a/src/array.jl
+++ b/src/array.jl
@@ -503,7 +503,7 @@ function Base.resize!(a::oneVector{T}, n::Integer) where {T}
     ctx = context(a)
     dev = device(a)
     buf = allocate(buftype(a), ctx, dev, bufsize, Base.datatype_alignment(T))
-    ptr = pointer(buf)
+    ptr = convert(ZePtr{T}, buf)
     m = min(length(a), n)
     if m > 0
         unsafe_copyto!(ctx, dev, ptr, pointer(a), m)