@ -61,48 +61,6 @@ enum CordRepKind {
FLAT = 3 ,
} ;
namespace {
// Type used with std::allocator for allocating and deallocating
// `CordRepExternal`. std::allocator is used because it opaquely handles the
// different new / delete overloads available on a given platform.
struct alignas ( absl : : cord_internal : : ExternalRepAlignment ( ) ) ExternalAllocType {
unsigned char value [ absl : : cord_internal : : ExternalRepAlignment ( ) ] ;
} ;
// Returns the number of objects to pass in to std::allocator<ExternalAllocType>
// allocate() and deallocate() to create enough room for `CordRepExternal` with
// `releaser_size` bytes on the end.
constexpr size_t GetExternalAllocNumObjects ( size_t releaser_size ) {
// Be sure to round up since `releaser_size` could be smaller than
// `sizeof(ExternalAllocType)`.
return ( sizeof ( CordRepExternal ) + releaser_size + sizeof ( ExternalAllocType ) -
1 ) /
sizeof ( ExternalAllocType ) ;
}
// Allocates enough memory for `CordRepExternal` and a releaser with size
// `releaser_size` bytes.
void * AllocateExternal ( size_t releaser_size ) {
return std : : allocator < ExternalAllocType > ( ) . allocate (
GetExternalAllocNumObjects ( releaser_size ) ) ;
}
// Deallocates the memory for a `CordRepExternal` assuming it was allocated with
// a releaser of given size and alignment.
void DeallocateExternal ( CordRepExternal * p , size_t releaser_size ) {
std : : allocator < ExternalAllocType > ( ) . deallocate (
reinterpret_cast < ExternalAllocType * > ( p ) ,
GetExternalAllocNumObjects ( releaser_size ) ) ;
}
// Returns a pointer to the type erased releaser for the given CordRepExternal.
void * GetExternalReleaser ( CordRepExternal * rep ) {
return rep + 1 ;
}
} // namespace
namespace cord_internal {
inline CordRepConcat * CordRep : : concat ( ) {
@ -304,11 +262,7 @@ static void UnrefInternal(CordRep* rep) {
}
} else if ( rep - > tag = = EXTERNAL ) {
CordRepExternal * rep_external = rep - > external ( ) ;
absl : : string_view data ( rep_external - > base , rep - > length ) ;
void * releaser = GetExternalReleaser ( rep_external ) ;
size_t releaser_size = rep_external - > releaser_invoker ( releaser , data ) ;
rep_external - > ~ CordRepExternal ( ) ;
DeallocateExternal ( rep_external , releaser_size ) ;
rep_external - > releaser_invoker ( rep_external ) ;
rep = nullptr ;
} else if ( rep - > tag = = SUBSTRING ) {
CordRepSubstring * rep_substring = rep - > substring ( ) ;
@ -458,18 +412,12 @@ static CordRep* NewTree(const char* data,
namespace cord_internal {
ExternalRepReleaserPair NewExternalWithUninitializedReleaser (
absl : : string_view data , ExternalReleaserInvoker invoker ,
size_t releaser_size ) {
void InitializeCordRepExternal ( absl : : string_view data , CordRepExternal * rep ) {
assert ( ! data . empty ( ) ) ;
void * raw_rep = AllocateExternal ( releaser_size ) ;
auto * rep = new ( raw_rep ) CordRepExternal ( ) ;
rep - > length = data . size ( ) ;
rep - > tag = EXTERNAL ;
rep - > base = data . data ( ) ;
rep - > releaser_invoker = invoker ;
return { VerifyTree ( rep ) , GetExternalReleaser ( rep ) } ;
VerifyTree ( rep ) ;
}
} // namespace cord_internal
@ -721,12 +669,12 @@ Cord::Cord(T&& src) {
std : : string data ;
} ;
const absl : : string_view original_data = src ;
CordRepExternal * rep =
static_cast < CordRepExternal * > ( absl : : cord_internal : : NewExternalRep (
original_data , StringReleaser { std : : move ( src ) } ) ) ;
auto * rep = static_cast <
: : absl : : cord_internal : : CordRepExternalImpl < StringReleaser > * > (
absl : : cord_internal : : NewExternalRep (
original_data , StringReleaser { std : : forward < T > ( src ) } ) ) ;
// Moving src may have invalidated its data pointer, so adjust it.
rep - > base =
static_cast < StringReleaser * > ( GetExternalReleaser ( rep ) ) - > data . data ( ) ;
rep - > base = rep - > template get < 0 > ( ) . data . data ( ) ;
contents_ . set_tree ( rep ) ;
}
}
@ -775,7 +723,7 @@ Cord& Cord::operator=(T&& src) {
if ( src . size ( ) < = kMaxBytesToCopy ) {
* this = absl : : string_view ( src ) ;
} else {
* this = Cord ( std : : move ( src ) ) ;
* this = Cord ( std : : forward < T > ( src ) ) ;
}
return * this ;
}
@ -898,7 +846,7 @@ void Cord::Append(T&& src) {
if ( src . size ( ) < = kMaxBytesToCopy ) {
Append ( absl : : string_view ( src ) ) ;
} else {
Append ( Cord ( std : : move ( src ) ) ) ;
Append ( Cord ( std : : forward < T > ( src ) ) ) ;
}
}
@ -938,7 +886,7 @@ inline void Cord::Prepend(T&& src) {
if ( src . size ( ) < = kMaxBytesToCopy ) {
Prepend ( absl : : string_view ( src ) ) ;
} else {
Prepend ( Cord ( std : : move ( src ) ) ) ;
Prepend ( Cord ( std : : forward < T > ( src ) ) ) ;
}
}
Abseil Team
4 years ago
committed by
Mark Barolak