diff options
Diffstat (limited to 'chromium/third_party/sqlite/sqlite-src-3240000/ext/fts5/fts5_varint.c')
-rw-r--r-- | chromium/third_party/sqlite/sqlite-src-3240000/ext/fts5/fts5_varint.c | 345 |
1 files changed, 0 insertions, 345 deletions
diff --git a/chromium/third_party/sqlite/sqlite-src-3240000/ext/fts5/fts5_varint.c b/chromium/third_party/sqlite/sqlite-src-3240000/ext/fts5/fts5_varint.c deleted file mode 100644 index bb212ab5a8a..00000000000 --- a/chromium/third_party/sqlite/sqlite-src-3240000/ext/fts5/fts5_varint.c +++ /dev/null @@ -1,345 +0,0 @@ -/* -** 2015 May 30 -** -** The author disclaims copyright to this source code. In place of -** a legal notice, here is a blessing: -** -** May you do good and not evil. -** May you find forgiveness for yourself and forgive others. -** May you share freely, never taking more than you give. -** -****************************************************************************** -** -** Routines for varint serialization and deserialization. -*/ - - -#include "fts5Int.h" - -/* -** This is a copy of the sqlite3GetVarint32() routine from the SQLite core. -** Except, this version does handle the single byte case that the core -** version depends on being handled before its function is called. -*/ -int sqlite3Fts5GetVarint32(const unsigned char *p, u32 *v){ - u32 a,b; - - /* The 1-byte case. Overwhelmingly the most common. */ - a = *p; - /* a: p0 (unmasked) */ - if (!(a&0x80)) - { - /* Values between 0 and 127 */ - *v = a; - return 1; - } - - /* The 2-byte case */ - p++; - b = *p; - /* b: p1 (unmasked) */ - if (!(b&0x80)) - { - /* Values between 128 and 16383 */ - a &= 0x7f; - a = a<<7; - *v = a | b; - return 2; - } - - /* The 3-byte case */ - p++; - a = a<<14; - a |= *p; - /* a: p0<<14 | p2 (unmasked) */ - if (!(a&0x80)) - { - /* Values between 16384 and 2097151 */ - a &= (0x7f<<14)|(0x7f); - b &= 0x7f; - b = b<<7; - *v = a | b; - return 3; - } - - /* A 32-bit varint is used to store size information in btrees. - ** Objects are rarely larger than 2MiB limit of a 3-byte varint. - ** A 3-byte varint is sufficient, for example, to record the size - ** of a 1048569-byte BLOB or string. - ** - ** We only unroll the first 1-, 2-, and 3- byte cases. The very - ** rare larger cases can be handled by the slower 64-bit varint - ** routine. - */ - { - u64 v64; - u8 n; - p -= 2; - n = sqlite3Fts5GetVarint(p, &v64); - *v = (u32)v64; - assert( n>3 && n<=9 ); - return n; - } -} - - -/* -** Bitmasks used by sqlite3GetVarint(). These precomputed constants -** are defined here rather than simply putting the constant expressions -** inline in order to work around bugs in the RVT compiler. -** -** SLOT_2_0 A mask for (0x7f<<14) | 0x7f -** -** SLOT_4_2_0 A mask for (0x7f<<28) | SLOT_2_0 -*/ -#define SLOT_2_0 0x001fc07f -#define SLOT_4_2_0 0xf01fc07f - -/* -** Read a 64-bit variable-length integer from memory starting at p[0]. -** Return the number of bytes read. The value is stored in *v. -*/ -u8 sqlite3Fts5GetVarint(const unsigned char *p, u64 *v){ - u32 a,b,s; - - a = *p; - /* a: p0 (unmasked) */ - if (!(a&0x80)) - { - *v = a; - return 1; - } - - p++; - b = *p; - /* b: p1 (unmasked) */ - if (!(b&0x80)) - { - a &= 0x7f; - a = a<<7; - a |= b; - *v = a; - return 2; - } - - /* Verify that constants are precomputed correctly */ - assert( SLOT_2_0 == ((0x7f<<14) | (0x7f)) ); - assert( SLOT_4_2_0 == ((0xfU<<28) | (0x7f<<14) | (0x7f)) ); - - p++; - a = a<<14; - a |= *p; - /* a: p0<<14 | p2 (unmasked) */ - if (!(a&0x80)) - { - a &= SLOT_2_0; - b &= 0x7f; - b = b<<7; - a |= b; - *v = a; - return 3; - } - - /* CSE1 from below */ - a &= SLOT_2_0; - p++; - b = b<<14; - b |= *p; - /* b: p1<<14 | p3 (unmasked) */ - if (!(b&0x80)) - { - b &= SLOT_2_0; - /* moved CSE1 up */ - /* a &= (0x7f<<14)|(0x7f); */ - a = a<<7; - a |= b; - *v = a; - return 4; - } - - /* a: p0<<14 | p2 (masked) */ - /* b: p1<<14 | p3 (unmasked) */ - /* 1:save off p0<<21 | p1<<14 | p2<<7 | p3 (masked) */ - /* moved CSE1 up */ - /* a &= (0x7f<<14)|(0x7f); */ - b &= SLOT_2_0; - s = a; - /* s: p0<<14 | p2 (masked) */ - - p++; - a = a<<14; - a |= *p; - /* a: p0<<28 | p2<<14 | p4 (unmasked) */ - if (!(a&0x80)) - { - /* we can skip these cause they were (effectively) done above in calc'ing s */ - /* a &= (0x7f<<28)|(0x7f<<14)|(0x7f); */ - /* b &= (0x7f<<14)|(0x7f); */ - b = b<<7; - a |= b; - s = s>>18; - *v = ((u64)s)<<32 | a; - return 5; - } - - /* 2:save off p0<<21 | p1<<14 | p2<<7 | p3 (masked) */ - s = s<<7; - s |= b; - /* s: p0<<21 | p1<<14 | p2<<7 | p3 (masked) */ - - p++; - b = b<<14; - b |= *p; - /* b: p1<<28 | p3<<14 | p5 (unmasked) */ - if (!(b&0x80)) - { - /* we can skip this cause it was (effectively) done above in calc'ing s */ - /* b &= (0x7f<<28)|(0x7f<<14)|(0x7f); */ - a &= SLOT_2_0; - a = a<<7; - a |= b; - s = s>>18; - *v = ((u64)s)<<32 | a; - return 6; - } - - p++; - a = a<<14; - a |= *p; - /* a: p2<<28 | p4<<14 | p6 (unmasked) */ - if (!(a&0x80)) - { - a &= SLOT_4_2_0; - b &= SLOT_2_0; - b = b<<7; - a |= b; - s = s>>11; - *v = ((u64)s)<<32 | a; - return 7; - } - - /* CSE2 from below */ - a &= SLOT_2_0; - p++; - b = b<<14; - b |= *p; - /* b: p3<<28 | p5<<14 | p7 (unmasked) */ - if (!(b&0x80)) - { - b &= SLOT_4_2_0; - /* moved CSE2 up */ - /* a &= (0x7f<<14)|(0x7f); */ - a = a<<7; - a |= b; - s = s>>4; - *v = ((u64)s)<<32 | a; - return 8; - } - - p++; - a = a<<15; - a |= *p; - /* a: p4<<29 | p6<<15 | p8 (unmasked) */ - - /* moved CSE2 up */ - /* a &= (0x7f<<29)|(0x7f<<15)|(0xff); */ - b &= SLOT_2_0; - b = b<<8; - a |= b; - - s = s<<4; - b = p[-4]; - b &= 0x7f; - b = b>>3; - s |= b; - - *v = ((u64)s)<<32 | a; - - return 9; -} - -/* -** The variable-length integer encoding is as follows: -** -** KEY: -** A = 0xxxxxxx 7 bits of data and one flag bit -** B = 1xxxxxxx 7 bits of data and one flag bit -** C = xxxxxxxx 8 bits of data -** -** 7 bits - A -** 14 bits - BA -** 21 bits - BBA -** 28 bits - BBBA -** 35 bits - BBBBA -** 42 bits - BBBBBA -** 49 bits - BBBBBBA -** 56 bits - BBBBBBBA -** 64 bits - BBBBBBBBC -*/ - -#ifdef SQLITE_NOINLINE -# define FTS5_NOINLINE SQLITE_NOINLINE -#else -# define FTS5_NOINLINE -#endif - -/* -** Write a 64-bit variable-length integer to memory starting at p[0]. -** The length of data write will be between 1 and 9 bytes. The number -** of bytes written is returned. -** -** A variable-length integer consists of the lower 7 bits of each byte -** for all bytes that have the 8th bit set and one byte with the 8th -** bit clear. Except, if we get to the 9th byte, it stores the full -** 8 bits and is the last byte. -*/ -static int FTS5_NOINLINE fts5PutVarint64(unsigned char *p, u64 v){ - int i, j, n; - u8 buf[10]; - if( v & (((u64)0xff000000)<<32) ){ - p[8] = (u8)v; - v >>= 8; - for(i=7; i>=0; i--){ - p[i] = (u8)((v & 0x7f) | 0x80); - v >>= 7; - } - return 9; - } - n = 0; - do{ - buf[n++] = (u8)((v & 0x7f) | 0x80); - v >>= 7; - }while( v!=0 ); - buf[0] &= 0x7f; - assert( n<=9 ); - for(i=0, j=n-1; j>=0; j--, i++){ - p[i] = buf[j]; - } - return n; -} - -int sqlite3Fts5PutVarint(unsigned char *p, u64 v){ - if( v<=0x7f ){ - p[0] = v&0x7f; - return 1; - } - if( v<=0x3fff ){ - p[0] = ((v>>7)&0x7f)|0x80; - p[1] = v&0x7f; - return 2; - } - return fts5PutVarint64(p,v); -} - - -int sqlite3Fts5GetVarintLen(u32 iVal){ -#if 0 - if( iVal<(1 << 7 ) ) return 1; -#endif - assert( iVal>=(1 << 7) ); - if( iVal<(1 << 14) ) return 2; - if( iVal<(1 << 21) ) return 3; - if( iVal<(1 << 28) ) return 4; - return 5; -} - |