add sizehint(Vector, sz). fixes JuliaLang#2230

pwl · Mar 4, 2013 · 6596099 · 6596099
1 parent cc4ae19
commit 6596099
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Showing 5 changed files with 17 additions and 1 deletion.
diff --git a/base/array.jl b/base/array.jl
@@ -675,6 +675,11 @@ function resize!(a::Vector, nl::Integer)
  return a
 end
 
+function sizehint(a::Vector, sz::Integer)
+ ccall(:jl_array_sizehint, Void, (Any, Uint), a, sz)
+ a
+end
+
 function pop!(a::Vector)
  if isempty(a)
  error("pop!: array is empty")

diff --git a/base/intset.jl b/base/intset.jl
@@ -23,7 +23,7 @@ function sizehint(s::IntSet, top::Integer)
  end
  s.limit = top
  end
- s.limit
+ s
 end
 
 function add!(s::IntSet, n::Integer)

diff --git a/src/array.c b/src/array.c
@@ -502,6 +502,15 @@ void jl_array_del_end(jl_array_t *a, size_t dec)
  a->length -= dec; a->nrows -= dec;
 }
 
+void jl_array_sizehint(jl_array_t *a, size_t sz)
+{
+ if (sz <= jl_array_len(a))
+ return;
+ size_t inc = sz - jl_array_len(a);
+ jl_array_grow_end(a, inc);
+ a->length -= inc; a->nrows -= inc;
+}
+
 void jl_array_grow_beg(jl_array_t *a, size_t inc)
 {
  // designed to handle the case of growing and shrinking at both ends

diff --git a/src/julia.expmap b/src/julia.expmap
@@ -53,6 +53,7 @@
  jl_array_del_end;
  jl_array_grow_beg;
  jl_array_grow_end;
+ jl_array_sizehint;
  jl_array_ptr;
  jl_arrayref;
  jl_arrayset;

diff --git a/src/julia.h b/src/julia.h
@@ -754,6 +754,7 @@ DLLEXPORT void jl_array_grow_end(jl_array_t *a, size_t inc);
 DLLEXPORT void jl_array_del_end(jl_array_t *a, size_t dec);
 DLLEXPORT void jl_array_grow_beg(jl_array_t *a, size_t inc);
 DLLEXPORT void jl_array_del_beg(jl_array_t *a, size_t dec);
+DLLEXPORT void jl_array_sizehint(jl_array_t *a, size_t sz);
 DLLEXPORT void *jl_value_ptr(jl_value_t *a);
 void jl_cell_1d_push(jl_array_t *a, jl_value_t *item);