authorgravatar for andrew@ziglang.orgAndrew Kelley <andrew@ziglang.org> 2017-12-11 17:27:31-05:00
committergravatar for andrew@ziglang.orgAndrew Kelley <andrew@ziglang.org> 2017-12-11 17:27:31-05:00
logc4e7d05ce37d60141afab997f23df33f5d4a218b
treec7f2fe66a890665c2db006d50495fba7ebddc455
parentd8d379faf1f656743d118e5e5cfa3dba1e537d65

refactor debug.global_allocator into mem.FixedBufferAllocator

3 files changed, 52 insertions(+), 40 deletions(-)

src-self-hosted/main.zig+4-2
......@@ -66,9 +66,11 @@ pub fn main2() -> %void {
6666}
6767
6868
69var fixed_buffer_mem: [100 * 1024]u8 = undefined;
70
6971fn testCanonical(source: []const u8) {
70 const allocator = std.debug.global_allocator;
71 std.debug.global_allocator_index = 0;
72 var fixed_allocator = mem.FixedBufferAllocator.init(fixed_buffer_mem[0..]);
73 const allocator = &fixed_allocator.allocator;
7274
7375 var tokenizer = Tokenizer.init(source);
7476 var parser = Parser.init(&tokenizer, allocator, "(memory buffer)");
std/debug.zig+3-38
......@@ -965,41 +965,6 @@ fn readILeb128(in_stream: &io.InStream) -> %i64 {
965965 }
966966}
967967
968pub const global_allocator = &global_allocator_state;
969
970var global_allocator_state = mem.Allocator {
971 .allocFn = globalAlloc,
972 .reallocFn = globalRealloc,
973 .freeFn = globalFree,
974};
975
976pub var global_allocator_mem: [100 * 1024]u8 = undefined;
977pub var global_allocator_index: usize = 0;
978
979error OutOfMemory;
980
981fn globalAlloc(self: &mem.Allocator, n: usize, alignment: u29) -> %[]u8 {
982 const addr = @ptrToInt(&global_allocator_mem[global_allocator_index]);
983 const rem = @rem(addr, alignment);
984 const march_forward_bytes = if (rem == 0) 0 else (alignment - rem);
985 const adjusted_index = global_allocator_index + march_forward_bytes;
986 const end_index = adjusted_index + n;
987 if (end_index > global_allocator_mem.len) {
988 return error.OutOfMemory;
989 }
990 const result = global_allocator_mem[adjusted_index .. end_index];
991 global_allocator_index = end_index;
992 return result;
993}
994
995fn globalRealloc(self: &mem.Allocator, old_mem: []u8, new_size: usize, alignment: u29) -> %[]u8 {
996 if (new_size <= old_mem.len) {
997 return old_mem[0..new_size];
998 } else {
999 const result = %return globalAlloc(self, new_size, alignment);
1000 @memcpy(result.ptr, old_mem.ptr, old_mem.len);
1001 return result;
1002 }
1003}
1004
1005fn globalFree(self: &mem.Allocator, memory: []u8) { }
968pub const global_allocator = &global_fixed_allocator.allocator;
969var global_fixed_allocator = mem.FixedBufferAllocator.init(global_allocator_mem[0..]);
970var global_allocator_mem: [100 * 1024]u8 = undefined;
std/mem.zig+45
......@@ -105,6 +105,51 @@ pub const Allocator = struct {
105105 }
106106};
107107
108pub const FixedBufferAllocator = struct {
109 allocator: Allocator,
110 end_index: usize,
111 buffer: []u8,
112
113 pub fn init(buffer: []u8) -> FixedBufferAllocator {
114 return FixedBufferAllocator {
115 .allocator = Allocator {
116 .allocFn = alloc,
117 .reallocFn = realloc,
118 .freeFn = free,
119 },
120 .buffer = buffer,
121 .end_index = 0,
122 };
123 }
124
125 fn alloc(allocator: &Allocator, n: usize, alignment: u29) -> %[]u8 {
126 const self = @fieldParentPtr(FixedBufferAllocator, "allocator", allocator);
127 const addr = @ptrToInt(&self.buffer[self.end_index]);
128 const rem = @rem(addr, alignment);
129 const march_forward_bytes = if (rem == 0) 0 else (alignment - rem);
130 const adjusted_index = self.end_index + march_forward_bytes;
131 const new_end_index = adjusted_index + n;
132 if (new_end_index > self.buffer.len) {
133 return error.OutOfMemory;
134 }
135 const result = self.buffer[adjusted_index .. new_end_index];
136 self.end_index = new_end_index;
137 return result;
138 }
139
140 fn realloc(allocator: &Allocator, old_mem: []u8, new_size: usize, alignment: u29) -> %[]u8 {
141 if (new_size <= old_mem.len) {
142 return old_mem[0..new_size];
143 } else {
144 const result = %return alloc(allocator, new_size, alignment);
145 copy(u8, result, old_mem);
146 return result;
147 }
148 }
149
150 fn free(allocator: &Allocator, bytes: []u8) { }
151};
152
108153
109154/// Copy all of source into dest at position 0.
110155/// dest.len must be >= source.len.