diff options
Diffstat (limited to 'upb/pb/varint.c')
| -rw-r--r-- | upb/pb/varint.c | 81 |
1 files changed, 43 insertions, 38 deletions
diff --git a/upb/pb/varint.c b/upb/pb/varint.c index 365deb4..04767eb 100644 --- a/upb/pb/varint.c +++ b/upb/pb/varint.c @@ -7,32 +7,33 @@ #include "upb/pb/varint.int.h" -// Index is descriptor type. +/* Index is descriptor type. */ const uint8_t upb_pb_native_wire_types[] = { - UPB_WIRE_TYPE_END_GROUP, // ENDGROUP - UPB_WIRE_TYPE_64BIT, // DOUBLE - UPB_WIRE_TYPE_32BIT, // FLOAT - UPB_WIRE_TYPE_VARINT, // INT64 - UPB_WIRE_TYPE_VARINT, // UINT64 - UPB_WIRE_TYPE_VARINT, // INT32 - UPB_WIRE_TYPE_64BIT, // FIXED64 - UPB_WIRE_TYPE_32BIT, // FIXED32 - UPB_WIRE_TYPE_VARINT, // BOOL - UPB_WIRE_TYPE_DELIMITED, // STRING - UPB_WIRE_TYPE_START_GROUP, // GROUP - UPB_WIRE_TYPE_DELIMITED, // MESSAGE - UPB_WIRE_TYPE_DELIMITED, // BYTES - UPB_WIRE_TYPE_VARINT, // UINT32 - UPB_WIRE_TYPE_VARINT, // ENUM - UPB_WIRE_TYPE_32BIT, // SFIXED32 - UPB_WIRE_TYPE_64BIT, // SFIXED64 - UPB_WIRE_TYPE_VARINT, // SINT32 - UPB_WIRE_TYPE_VARINT, // SINT64 + UPB_WIRE_TYPE_END_GROUP, /* ENDGROUP */ + UPB_WIRE_TYPE_64BIT, /* DOUBLE */ + UPB_WIRE_TYPE_32BIT, /* FLOAT */ + UPB_WIRE_TYPE_VARINT, /* INT64 */ + UPB_WIRE_TYPE_VARINT, /* UINT64 */ + UPB_WIRE_TYPE_VARINT, /* INT32 */ + UPB_WIRE_TYPE_64BIT, /* FIXED64 */ + UPB_WIRE_TYPE_32BIT, /* FIXED32 */ + UPB_WIRE_TYPE_VARINT, /* BOOL */ + UPB_WIRE_TYPE_DELIMITED, /* STRING */ + UPB_WIRE_TYPE_START_GROUP, /* GROUP */ + UPB_WIRE_TYPE_DELIMITED, /* MESSAGE */ + UPB_WIRE_TYPE_DELIMITED, /* BYTES */ + UPB_WIRE_TYPE_VARINT, /* UINT32 */ + UPB_WIRE_TYPE_VARINT, /* ENUM */ + UPB_WIRE_TYPE_32BIT, /* SFIXED32 */ + UPB_WIRE_TYPE_64BIT, /* SFIXED64 */ + UPB_WIRE_TYPE_VARINT, /* SINT32 */ + UPB_WIRE_TYPE_VARINT, /* SINT64 */ }; -// A basic branch-based decoder, uses 32-bit values to get good performance -// on 32-bit architectures (but performs well on 64-bits also). -// This scheme comes from the original Google Protobuf implementation (proto2). +/* A basic branch-based decoder, uses 32-bit values to get good performance + * on 32-bit architectures (but performs well on 64-bits also). + * This scheme comes from the original Google Protobuf implementation + * (proto2). */ upb_decoderet upb_vdecode_max8_branch32(upb_decoderet r) { upb_decoderet err = {NULL, 0}; const char *p = r.p; @@ -56,7 +57,7 @@ done: return r; } -// Like the previous, but uses 64-bit values. +/* Like the previous, but uses 64-bit values. */ upb_decoderet upb_vdecode_max8_branch64(upb_decoderet r) { const char *p = r.p; uint64_t val = r.val; @@ -78,49 +79,53 @@ done: return r; } -// Given an encoded varint v, returns an integer with a single bit set that -// indicates the end of the varint. Subtracting one from this value will -// yield a mask that leaves only bits that are part of the varint. Returns -// 0 if the varint is unterminated. +/* Given an encoded varint v, returns an integer with a single bit set that + * indicates the end of the varint. Subtracting one from this value will + * yield a mask that leaves only bits that are part of the varint. Returns + * 0 if the varint is unterminated. */ static uint64_t upb_get_vstopbit(uint64_t v) { uint64_t cbits = v | 0x7f7f7f7f7f7f7f7fULL; return ~cbits & (cbits+1); } -// A branchless decoder. Credit to Pascal Massimino for the bit-twiddling. +/* A branchless decoder. Credit to Pascal Massimino for the bit-twiddling. */ upb_decoderet upb_vdecode_max8_massimino(upb_decoderet r) { uint64_t b; + uint64_t stop_bit; + upb_decoderet my_r; memcpy(&b, r.p, sizeof(b)); - uint64_t stop_bit = upb_get_vstopbit(b); + stop_bit = upb_get_vstopbit(b); b = (b & 0x7f7f7f7f7f7f7f7fULL) & (stop_bit - 1); b += b & 0x007f007f007f007fULL; b += 3 * (b & 0x0000ffff0000ffffULL); b += 15 * (b & 0x00000000ffffffffULL); if (stop_bit == 0) { - // Error: unterminated varint. + /* Error: unterminated varint. */ upb_decoderet err_r = {(void*)0, 0}; return err_r; } - upb_decoderet my_r = {r.p + ((__builtin_ctzll(stop_bit) + 1) / 8), - r.val | (b << 7)}; + my_r = upb_decoderet_make(r.p + ((__builtin_ctzll(stop_bit) + 1) / 8), + r.val | (b << 7)); return my_r; } -// A branchless decoder. Credit to Daniel Wright for the bit-twiddling. +/* A branchless decoder. Credit to Daniel Wright for the bit-twiddling. */ upb_decoderet upb_vdecode_max8_wright(upb_decoderet r) { uint64_t b; + uint64_t stop_bit; + upb_decoderet my_r; memcpy(&b, r.p, sizeof(b)); - uint64_t stop_bit = upb_get_vstopbit(b); + stop_bit = upb_get_vstopbit(b); b &= (stop_bit - 1); b = ((b & 0x7f007f007f007f00ULL) >> 1) | (b & 0x007f007f007f007fULL); b = ((b & 0xffff0000ffff0000ULL) >> 2) | (b & 0x0000ffff0000ffffULL); b = ((b & 0xffffffff00000000ULL) >> 4) | (b & 0x00000000ffffffffULL); if (stop_bit == 0) { - // Error: unterminated varint. + /* Error: unterminated varint. */ upb_decoderet err_r = {(void*)0, 0}; return err_r; } - upb_decoderet my_r = {r.p + ((__builtin_ctzll(stop_bit) + 1) / 8), - r.val | (b << 14)}; + my_r = upb_decoderet_make(r.p + ((__builtin_ctzll(stop_bit) + 1) / 8), + r.val | (b << 14)); return my_r; } |