Remove backward_bytes feature

Author: Keats

Cargo.toml

@@ -10,9 +10,6 @@ memmap = "0.7.0"
 murmurhash3 = "0.0.5"
 once_cell = "1.3.1"
 
-[features]
-backward_bytes = []
-
 [dev-dependencies]
 criterion = "0.3"
 

src/mmap_bitvec.rs

@@ -244,7 +244,7 @@ impl MmapBitVec {
         // `shift` is the same as the position of the last bit
         let shift = (r.end & 7) as u8;
         for (new_idx, old_idx) in (byte_idx_st..=byte_idx_en).enumerate() {
-            let old_val = unsafe { order_byte(*ptr.add(old_idx)) };
+            let old_val = unsafe { *ptr.add(old_idx) };
             if new_idx > 0 {
                 if let Some(shifted_val) = old_val.checked_shr(u32::from(shift)) {
                     v[new_idx - 1] |= shifted_val;
@@ -295,12 +295,12 @@ impl MmapBitVec {
             let shifted_val = val.checked_shr(u32::from(8 - shift)).unwrap_or(0);
             if idx > 0 && shift != 8 {
                 unsafe {
-                    *mmap.offset(idx as isize - 1) |= order_byte(shifted_val);
+                    *mmap.offset(idx as isize - 1) |= shifted_val;
                 }
             }
             let shifted_val = (val & mask).checked_shl(u32::from(shift)).unwrap_or(*val);
             unsafe {
-                *mmap.add(idx) |= order_byte(shifted_val);
+                *mmap.add(idx) |= shifted_val;
             }
         }
     }
@@ -317,10 +317,7 @@ impl BitVector for MmapBitVec {
             panic!("Invalid bit vector index");
         }
         let byte_idx = (i >> 3) as isize;
-        #[cfg(not(feature = "backward_bytes"))]
         let bit_idx = 7 - (i & 7) as u8;
-        #[cfg(feature = "backward_bytes")]
-        let bit_idx = (i & 7) as u8;
 
         let mmap: *const u8 = self.mmap.as_ptr();
         unsafe { (*mmap.offset(byte_idx) & (1 << bit_idx)) != 0 }
@@ -336,10 +333,7 @@ impl BitVector for MmapBitVec {
             panic!("Invalid bit vector index");
         }
         let byte_idx = (i >> 3) as isize;
-        #[cfg(not(feature = "backward_bytes"))]
         let bit_idx = 7 - (i & 7) as u8;
-        #[cfg(feature = "backward_bytes")]
-        let bit_idx = (i & 7) as u8;
 
         let mmap: *mut u8 = self.mmap.as_mut_ptr();
         unsafe {
@@ -368,7 +362,7 @@ impl BitVector for MmapBitVec {
             size_front = 0;
         }
         if let Some(mask) = 0xFFu8.checked_shl(u32::from(size_front)) {
-            let byte = unsafe { *mmap.add(byte_idx_st) & order_byte(mask) };
+            let byte = unsafe { *mmap.add(byte_idx_st) & mask };
             bit_count += byte.count_ones() as usize
         }
 
@@ -383,7 +377,7 @@ impl BitVector for MmapBitVec {
             size_back = 0;
         }
         if let Some(mask) = 0xFFu8.checked_shr(u32::from(size_back)) {
-            let byte = unsafe { *mmap.add(byte_idx_en) & order_byte(mask) };
+            let byte = unsafe { *mmap.add(byte_idx_en) & mask };
             bit_count += byte.count_ones() as usize
         }
 
@@ -453,12 +447,12 @@ impl BitVector for MmapBitVec {
 
         // read the last byte first
         unsafe {
-            v = u128::from(order_byte(*ptr.add(byte_idx_en)));
+            v = u128::from(*ptr.add(byte_idx_en));
         }
         // align the end of the data with the end of the u128
         v >>= 7 - ((r.end - 1) & 7);
 
-        if r.start < self.size - 128usize && cfg!(not(feature = "backward_bytes")) {
+        if r.start < self.size - 128usize {
             // really nasty/unsafe, but we're just reading a u64/u128 out instead of doing it
             // byte-wise --- also does not work with legacy mode!!!
             unsafe {
@@ -472,8 +466,7 @@ impl BitVector for MmapBitVec {
             let bit_offset = new_size + (r.start & 7) as u8;
             for (new_idx, old_idx) in (byte_idx_st..byte_idx_en).enumerate() {
                 unsafe {
-                    v |= u128::from(order_byte(*ptr.add(old_idx)))
-                        << (bit_offset - 8u8 * (new_idx as u8 + 1));
+                    v |= u128::from(*ptr.add(old_idx)) << (bit_offset - 8u8 * (new_idx as u8 + 1));
                 }
             }
         }
@@ -511,7 +504,7 @@ impl BitVector for MmapBitVec {
         // new value get masked over the existing 1's
         let mmap: *mut u8 = self.mmap.as_mut_ptr();
         unsafe {
-            *mmap.add(byte_idx_st) |= order_byte(front_byte);
+            *mmap.add(byte_idx_st) |= front_byte;
         }
 
         // if the front is all there is, we can bail now
@@ -526,7 +519,7 @@ impl BitVector for MmapBitVec {
         }
         let back_byte = (x << (128 - size_back) >> 120) as u8;
         unsafe {
-            *mmap.add(byte_idx_en) |= order_byte(back_byte);
+            *mmap.add(byte_idx_en) |= back_byte;
         }
 
         // only two bytes long, bail out
@@ -546,7 +539,7 @@ impl BitVector for MmapBitVec {
         }
         for (byte_idx, byte) in ((byte_idx_st + 1)..byte_idx_en).zip(bytes.iter()) {
             unsafe {
-                *mmap.add(byte_idx) |= order_byte(*byte);
+                *mmap.add(byte_idx) |= *byte;
             }
         }
     }
@@ -565,7 +558,7 @@ impl BitVector for MmapBitVec {
         let size_front = 8u8 - (r.start & 7) as u8;
         if let Some(mask) = 0xFFu8.checked_shl(u32::from(size_front)) {
             unsafe {
-                *mmap.add(byte_idx_st) &= order_byte(mask);
+                *mmap.add(byte_idx_st) &= mask;
             }
         }
 
@@ -581,7 +574,7 @@ impl BitVector for MmapBitVec {
         }
         if let Some(mask) = 0xFFu8.checked_shr(u32::from(size_back)) {
             unsafe {
-                *mmap.add(byte_idx_en) &= order_byte(mask);
+                *mmap.add(byte_idx_en) &= mask;
             }
         }
 
@@ -607,36 +600,6 @@ impl Drop for MmapBitVec {
     }
 }
 
-#[inline]
-#[cfg(not(feature = "backward_bytes"))]
-fn order_byte(b: u8) -> u8 {
-    b
-}
-
-#[inline]
-#[cfg(feature = "backward_bytes")]
-fn order_byte(b: u8) -> u8 {
-    // in python: ','.join(str(eval('{:08b}b0'.format(i)[::-1])) for i in range(256))
-    #[rustfmt::skip]
-    const BACKWARDS: [u8; 256] = [
-        0,128,64,192,32,160,96,224,16,144,80,208,48,176,112,240,8,136,72,
-        200,40,168,104,232,24,152,88,216,56,184,120,248,4,132,68,196,36,
-        164,100,228,20,148,84,212,52,180,116,244,12,140,76,204,44,172,108,
-        236,28,156,92,220,60,188,124,252,2,130,66,194,34,162,98,226,18,146,
-        82,210,50,178,114,242,10,138,74,202,42,170,106,234,26,154,90,218,58,
-        186,122,250,6,134,70,198,38,166,102,230,22,150,86,214,54,182,118,246,
-        14,142,78,206,46,174,110,238,30,158,94,222,62,190,126,254,1,129,65,
-        193,33,161,97,225,17,145,81,209,49,177,113,241,9,137,73,201,41,169,
-        105,233,25,153,89,217,57,185,121,249,5,133,69,197,37,165,101,229,21,
-        149,85,213,53,181,117,245,13,141,77,205,45,173,109,237,29,157,93,221,
-        61,189,125,253,3,131,67,195,35,163,99,227,19,147,83,211,51,179,115,
-        243,11,139,75,203,43,171,107,235,27,155,91,219,59,187,123,251,7,135,
-        71,199,39,167,103,231,23,151,87,215,55,183,119,247,15,143,79,207,47,
-        175,111,239,31,159,95,223,63,191,127,255
-    ];
-    BACKWARDS[b as usize]
-}
-
 #[cfg(test)]
 mod test {
     use std::path::Path;