diff options
Diffstat (limited to 'src/sds.h')
| -rw-r--r-- | src/sds.h | 68 |
1 files changed, 47 insertions, 21 deletions
@@ -39,43 +39,53 @@ typedef char *sds; +/* Note: sdshdr5 is never used, we just access the flags byte directly. + * However is here to document the layout of type 5 SDS strings. */ +struct __attribute__ ((__packed__)) sdshdr5 { + unsigned char flags; /* 3 lsb of type, and 5 msb of string length */ + char buf[]; +}; struct __attribute__ ((__packed__)) sdshdr8 { uint8_t len; /* used */ uint8_t alloc; /* excluding the header and null terminator */ - char flags; /* 2 lsb of type, and 6 msb of refcount */ + unsigned char flags; /* 3 lsb of type, 5 unused bits */ char buf[]; }; struct __attribute__ ((__packed__)) sdshdr16 { uint16_t len; /* used */ uint16_t alloc; /* excluding the header and null terminator */ - char flags; /* 2 lsb of type, and 6 msb of refcount */ + unsigned char flags; /* 3 lsb of type, 5 unused bits */ char buf[]; }; struct __attribute__ ((__packed__)) sdshdr32 { uint32_t len; /* used */ uint32_t alloc; /* excluding the header and null terminator */ - char flags; /* 2 lsb of type, and 6 msb of refcount */ + unsigned char flags; /* 3 lsb of type, 5 unused bits */ char buf[]; }; struct __attribute__ ((__packed__)) sdshdr64 { uint64_t len; /* used */ uint64_t alloc; /* excluding the header and null terminator */ - char flags; /* 2 lsb of type, and 6 msb of refcount */ + unsigned char flags; /* 3 lsb of type, 5 unused bits */ char buf[]; }; -#define SDS_TYPE_8 0 -#define SDS_TYPE_16 1 -#define SDS_TYPE_32 2 -#define SDS_TYPE_64 3 -#define SDS_TYPE_MASK 3 -#define SDS_TYPE_BITS 2 +#define SDS_TYPE_5 0 +#define SDS_TYPE_8 1 +#define SDS_TYPE_16 2 +#define SDS_TYPE_32 3 +#define SDS_TYPE_64 4 +#define SDS_TYPE_MASK 7 +#define SDS_TYPE_BITS 3 #define SDS_HDR_VAR(T,s) struct sdshdr##T *sh = (void*)((s)-(sizeof(struct sdshdr##T))); #define SDS_HDR(T,s) ((struct sdshdr##T *)((s)-(sizeof(struct sdshdr##T)))) +#define SDS_TYPE_5_LEN(f) ((f)>>SDS_TYPE_BITS) static inline size_t sdslen(const sds s) { - char flags = s[-1]; + unsigned char flags = s[-1]; switch(flags&SDS_TYPE_MASK) { + case SDS_TYPE_5: + return SDS_TYPE_5_LEN(flags); case SDS_TYPE_8: return SDS_HDR(8,s)->len; case SDS_TYPE_16: @@ -89,8 +99,11 @@ static inline size_t sdslen(const sds s) { } static inline size_t sdsavail(const sds s) { - char flags = s[-1]; + unsigned char flags = s[-1]; switch(flags&SDS_TYPE_MASK) { + case SDS_TYPE_5: { + return 0; + } case SDS_TYPE_8: { SDS_HDR_VAR(8,s); return sh->alloc - sh->len; @@ -112,8 +125,14 @@ static inline size_t sdsavail(const sds s) { } static inline void sdssetlen(sds s, size_t newlen) { - char flags = s[-1]; + unsigned char flags = s[-1]; switch(flags&SDS_TYPE_MASK) { + case SDS_TYPE_5: + { + unsigned char *fp = ((unsigned char*)s)-1; + *fp = SDS_TYPE_5 | (newlen << SDS_TYPE_BITS); + } + break; case SDS_TYPE_8: SDS_HDR(8,s)->len = newlen; break; @@ -130,8 +149,15 @@ static inline void sdssetlen(sds s, size_t newlen) { } static inline void sdsinclen(sds s, size_t inc) { - char flags = s[-1]; + unsigned char flags = s[-1]; switch(flags&SDS_TYPE_MASK) { + case SDS_TYPE_5: + { + unsigned char *fp = ((unsigned char*)s)-1; + unsigned char newlen = SDS_TYPE_5_LEN(flags)+inc; + *fp = SDS_TYPE_5 | (newlen << SDS_TYPE_BITS); + } + break; case SDS_TYPE_8: SDS_HDR(8,s)->len += inc; break; @@ -149,8 +175,10 @@ static inline void sdsinclen(sds s, size_t inc) { /* sdsalloc() = sdsavail() + sdslen() */ static inline size_t sdsalloc(const sds s) { - char flags = s[-1]; + unsigned char flags = s[-1]; switch(flags&SDS_TYPE_MASK) { + case SDS_TYPE_5: + return SDS_TYPE_5_LEN(flags); case SDS_TYPE_8: return SDS_HDR(8,s)->alloc; case SDS_TYPE_16: @@ -164,8 +192,11 @@ static inline size_t sdsalloc(const sds s) { } static inline void sdssetalloc(sds s, size_t newlen) { - char flags = s[-1]; + unsigned char flags = s[-1]; switch(flags&SDS_TYPE_MASK) { + case SDS_TYPE_5: + /* Nothing to do, this type has no total allocation info. */ + break; case SDS_TYPE_8: SDS_HDR(8,s)->alloc = newlen; break; @@ -193,11 +224,6 @@ sds sdscatsds(sds s, const sds t); sds sdscpylen(sds s, const char *t, size_t len); sds sdscpy(sds s, const char *t); -/* we can add a reference count on top of any - * existing sds. (max up to 63 references) */ -void sdsIncRefcount(sds s); -void sdsDecRefcount(sds s); - sds sdscatvprintf(sds s, const char *fmt, va_list ap); #ifdef __GNUC__ sds sdscatprintf(sds s, const char *fmt, ...) |