authorgravatar for 4678790+dweiller@users.noreply.github.comDominic <4678790+dweiller@users.noreply.github.com> 2024-03-10 18:17:23+11:00
committergravatar for 4678790+dweiller@users.noreply.github.comDominic <4678790+dweiller@users.noreply.github.com> 2024-03-10 18:17:23+11:00
log6fe2b4077896218083f778e926217f596a58a550
treee4a10e0730a4ca102e74aefadfedb1c2203bd7bf
parentd942096a448d70f7dd8be747c120df8f10c6c723

std.RingBuffer: use sliceAt/sliceFirst in read*AssumeLength

1 files changed, 14 insertions(+), 13 deletions(-)

lib/std/RingBuffer.zig+14-13
...@@ -150,12 +150,8 @@ pub fn readFirst(self: *RingBuffer, dest: []u8, length: usize) Error!void {...@@ -150,12 +150,8 @@ pub fn readFirst(self: *RingBuffer, dest: []u8, length: usize) Error!void {
150/// Uses memcpy and so `dest` must not overlap ring buffer data.150/// Uses memcpy and so `dest` must not overlap ring buffer data.
151pub fn readFirstAssumeLength(self: *RingBuffer, dest: []u8, length: usize) void {151pub fn readFirstAssumeLength(self: *RingBuffer, dest: []u8, length: usize) void {
152 assert(length <= self.len() and length <= dest.len);152 assert(length <= self.len() and length <= dest.len);
153 const data_start = self.mask(self.read_index);153 const slice = self.sliceAt(self.read_index, length);
154 const part1_data_end = @min(self.data.len, data_start + length);154 slice.copyTo(dest);
155 const part1_len = part1_data_end - data_start;
156 const part2_len = length - part1_len;
157 @memcpy(dest[0..part1_len], self.data[data_start..part1_data_end]);
158 @memcpy(dest[part1_len..length], self.data[0..part2_len]);
159 self.read_index = self.mask2(self.read_index + length);155 self.read_index = self.mask2(self.read_index + length);
160}156}
161157
...@@ -174,13 +170,12 @@ pub fn readLast(self: *RingBuffer, dest: []u8, length: usize) Error!void {...@@ -174,13 +170,12 @@ pub fn readLast(self: *RingBuffer, dest: []u8, length: usize) Error!void {
174/// Reduces write index by `length`.170/// Reduces write index by `length`.
175pub fn readLastAssumeLength(self: *RingBuffer, dest: []u8, length: usize) void {171pub fn readLastAssumeLength(self: *RingBuffer, dest: []u8, length: usize) void {
176 assert(length <= self.len() and length <= dest.len);172 assert(length <= self.len() and length <= dest.len);
177 const data_start = self.mask(self.write_index + self.data.len - length);173 const slice = self.sliceLast(length);
178 const part1_data_end = @min(self.data.len, data_start + length);174 slice.copyTo(dest);
179 const part1_len = part1_data_end - data_start;175 self.write_index = if (self.write_index >= self.data.len)
180 const part2_len = length - part1_len;176 self.write_index - length
181 @memcpy(dest[0..part1_len], self.data[data_start..part1_data_end]);177 else
182 @memcpy(dest[part1_len..length], self.data[0..part2_len]);178 self.mask(self.write_index + self.data.len - length);
183 self.write_index = if (self.write_index >= self.data.len) self.write_index - length else data_start;
184}179}
185180
186/// Returns `true` if the ring buffer is empty and `false` otherwise.181/// Returns `true` if the ring buffer is empty and `false` otherwise.
...@@ -206,6 +201,12 @@ pub fn len(self: RingBuffer) usize {...@@ -206,6 +201,12 @@ pub fn len(self: RingBuffer) usize {
206pub const Slice = struct {201pub const Slice = struct {
207 first: []u8,202 first: []u8,
208 second: []u8,203 second: []u8,
204
205 /// Copy data from `self` into `dest`
206 pub fn copyTo(self: Slice, dest: []u8) void {
207 @memcpy(dest[0..self.first.len], self.first);
208 @memcpy(dest[self.first.len..][0..self.second.len], self.second);
209 }
209};210};
210211
211/// Returns a `Slice` for the region of the ring buffer starting at212/// Returns a `Slice` for the region of the ring buffer starting at