diff options
Diffstat (limited to 'lib/qstring.h')
| -rw-r--r-- | lib/qstring.h | 247 |
1 files changed, 175 insertions, 72 deletions
diff --git a/lib/qstring.h b/lib/qstring.h index 1841657e..0597eda8 100644 --- a/lib/qstring.h +++ b/lib/qstring.h @@ -27,6 +27,8 @@ #include <stddef.h> #include <stdint.h> +#include "memory.h" + #ifndef Inline #define Inline static inline #endif @@ -39,10 +41,14 @@ #endif /* __GNUC__ */ /*============================================================================== - * These "qstrings" address the ... - * + * These "qstrings" address address the lack of a flexible length string in 'C'. * + * This is not a general purpose strings module, but provides a limited number + * of useful string operations such that the caller does not need to worry + * about the length of the string, and allocating space and so on. * + * The caller does, however, have to explicitly release the contents of a + * qstring when it is done with. */ typedef struct qstring qstring_t ; @@ -50,7 +56,13 @@ typedef struct qstring* qstring ; struct qstring { - void* body ; + union + { + void* body ; + const void* const_body ; + char* char_body ; + unsigned char* uchar_body ; + } ; size_t size ; size_t len ; @@ -115,117 +127,161 @@ qs_ep_byte(qstring qs) * Functions */ -extern qstring -qs_init_new(qstring qs, size_t len) ; - -extern size_t -qs_alloc(qstring qs, size_t len) ; - -extern void -qs_free_body(qstring qs) ; - -extern qstring -qs_reset(qstring qs, int free_structure) ; +extern qstring qs_init_new(qstring qs, size_t len) ; +extern qstring qs_make_to_length(qstring qs, size_t len) ; +extern void qs_free_body(qstring qs) ; +extern qstring qs_reset(qstring qs, int free_structure) ; #define qs_reset_keep(qs) qs_reset(qs, 0) #define qs_reset_free(qs) qs_reset(qs, 1) -extern int -qs_printf(qstring qs, const char* format, ...) PRINTF_ATTRIBUTE(2, 3) ; +Inline qstring qs_new(void) ; +Inline qstring qs_dummy(qstring qs, const char* src, int pos) ; -extern int -qs_vprintf(qstring qs, const char *format, va_list args) ; +extern qstring qs_printf(qstring qs, const char* format, ...) + PRINTF_ATTRIBUTE(2, 3) ; +extern qstring qs_vprintf(qstring qs, const char *format, va_list args) ; -extern size_t -qs_set(qstring qs, const char* s) ; +extern qstring qs_set(qstring qs, const char* src) ; +extern qstring qs_set_n(qstring qs, const char* src, size_t n) ; -extern size_t -qs_set_n(qstring qs, const char* s, size_t len) ; +extern qstring qs_append(qstring qs, const char* src) ; +extern qstring qs_append_n(qstring qs, const char* src, size_t n) ; -Inline size_t -qs_need(qstring qs, size_t len) ; +Inline qstring qs_need(qstring qs, size_t len) ; +Inline qstring qs_set_len(qstring qs, size_t len) ; +extern qstring qs_add_len(qstring qs, size_t n, char** p_ep) ; +Inline void qs_clear(qstring qs) ; +Inline size_t qs_len(qstring qs) ; +Inline size_t qs_size(qstring qs) ; +Inline void* qs_term(qstring qs) ; -Inline size_t -qs_set_len(qstring qs, size_t len) ; +Inline size_t qs_insert(qstring qs, const void* src, size_t n) ; +Inline void qs_replace(qstring qs, const void* src, size_t n) ; +Inline size_t qs_delete(qstring qs, size_t n) ; -Inline void -qs_set_empty(qstring qs) ; +extern qstring qs_copy(qstring dst, qstring src) ; +extern int qs_cmp_sig(qstring a, qstring b) ; -Inline size_t -qs_len(qstring qs) ; - -Inline size_t -qs_size(qstring qs) ; - -Inline void* -qs_term(qstring qs) ; +/*============================================================================== + * The Inline functions. + */ -Inline size_t -qs_insert(qstring qs, const void* src, size_t n) ; +/*------------------------------------------------------------------------------ + * Make a brand new, completely empty qstring + */ +Inline qstring +qs_new(void) +{ + /* Zeroising has set: + * + * body = NULL -- no body + * size = 0 -- no body + * + * len = 0 + * cp = 0 + * + * Nothing more to do unless initial size != 0 + */ + return XCALLOC(MTYPE_QSTRING, sizeof(qstring_t)) ; +} ; -Inline void -qs_replace(qstring qs, const void* src, size_t n) ; +/*------------------------------------------------------------------------------ + * Construct a "dummy" qstring from the given string. + * + * Allocates a qstring if required. + * + * This sets: body = the src + * len = strlen(src) (0 if src is NULL) + * cp = 0 if 'pos' is zero + * len otherwise + * size = 0 + * + * The zero size means that the qstring handling will not attempt to free + * the body, nor will it write to it... Operations which require the qstring + * to have a size will allocate a new body, and discard this one. + * + * Returns: the address of the dummy qstring. + */ +Inline qstring +qs_dummy(qstring qs, const char* src, int pos) +{ + if (qs == NULL) + qs = qs_new() ; -Inline size_t -qs_delete(qstring qs, size_t n) ; + qs->const_body = src ; + qs->len = (src != NULL) ? strlen(src) : 0 ; + qs->cp = (pos == 0) ? 0 : qs->len ; + qs->size = 0 ; -/*============================================================================== - * The Inline functions. - */ + return qs ; +} /*------------------------------------------------------------------------------ * Need space for a string of 'len' characters (plus possible '\0'). * - * Returns: size of the qstring body - * (which includes the extra space allowed for '\0') + * Allocates the qstring, if required. + * + * Returns: address of qstring * * NB: asking for 0 bytes will cause a body to be allocated, ready for any * '\0' ! * - * NB: has no effect on 'cp' or 'len'. + * NB: has no effect on 'cp' or 'len'. (Will be zero if new qstring allocated.) */ -Inline size_t +Inline qstring qs_need(qstring qs, size_t len) { - if (len < qs->size) - { - assert(qs->body != NULL) ; - return qs->size ; - } - else - return qs_alloc(qs, len) ; + if ((qs == NULL) || (len >= qs->size)) + return qs_make_to_length(qs, len) ; + + assert(qs->body != NULL) ; + return qs ; } ; /*------------------------------------------------------------------------------ * Set 'len' -- allocate or extend body as required. * - * Returns: size of the qstring body - * (which includes the extra space allowed for '\0') + * Allocates the qstring, if required. * - * NB: asking for 0 bytes will cause a body to be allocated, ready for any + * Returns: address of qstring + * + * NB: setting len == 0 bytes will cause a body to be allocated, ready for any * '\0' ! * * NB: has no effect on 'cp' -- even if 'cp' > 'len'. + * + * NB: if this is a "dummy" qstring, a copy is made of the original body. */ -Inline size_t +Inline qstring qs_set_len(qstring qs, size_t len) { + qs = qs_need(qs, len) ; qs->len = len ; - return qs_need(qs, len) ; + return qs ; } ; /*------------------------------------------------------------------------------ * Reset contents of qstring. * + * Does nothing if qstring is NULL + * * Sets 'cp' = 'len' = 0. Sets first byte of body (if any) to NULL. + * + * For "dummy" qstring, discards the body. */ Inline void -qs_set_empty(qstring qs) +qs_clear(qstring qs) { - qs->len = 0 ; - qs->cp = 0 ; - if (qs->body != NULL) - *((char*)qs->body) = '\0' ; + if (qs != NULL) + { + qs->len = 0 ; + qs->cp = 0 ; + if (qs->size > 0) + *((char*)qs->body) = '\0' ; + else + qs->body = NULL ; + } ; } ; /*------------------------------------------------------------------------------ @@ -238,31 +294,63 @@ qs_set_empty(qstring qs) Inline size_t qs_len(qstring qs) { - return qs->len = (qs->body != NULL) ? strlen(qs_chars(qs)) : 0 ; + return (qs != NULL) ? (qs->len = (qs->body != NULL) ? strlen(qs_chars(qs)) + : 0) + : 0 ; } ; /*------------------------------------------------------------------------------ * Get size of qstring body. * - * NB: if no body has been allocated, size = 0 + * NB: if no body has been allocated, size == 0 + * if qstring is NULL, size == 0 + * + * NB: if this is a "dummy" qstring, size == 0. */ Inline size_t qs_size(qstring qs) { - return qs->size ; + return (qs != NULL) ? qs->size : 0 ; +} ; + +/*------------------------------------------------------------------------------ + * Get address of current end of qstring body -- ie byte at 'len'. + * + * NB: allocates body if required. + * + * There will be space for '\0' after 'len', so the address returned + * is within the real body of the string. + * + * NB: if this is a "dummy" qstring, a copy is made of the original body. + * + * NB: address of qstring may NOT be NULL. + */ +Inline void* +qs_end(qstring qs) +{ + if (qs->len >= qs->size) + qs_make_to_length(qs, qs->len) ; /* allows for trailing '\0' */ + + return (char*)qs->body + qs->len ; } ; /*------------------------------------------------------------------------------ * Set '\0' at qs->len -- allocate or extend body as required. * - * Returns address of body. + * Returns address of body -- NULL if the qstring is NULL + * + * NB: if this is a "dummy" qstring, a copy is made of the original body. */ Inline void* qs_term(qstring qs) { size_t len ; + + if (qs == NULL) + return NULL ; + if ((len = qs->len) >= qs->size) - qs_alloc(qs, len) ; + qs_make_to_length(qs, len) ; *qs_chars_at(qs, len) = '\0' ; @@ -276,10 +364,14 @@ qs_term(qstring qs) * * Returns: number of bytes beyond 'cp' that were moved before insert. * + * NB: qstring MUST NOT be NULL + * * NB: if 'cp' > 'len', then sets 'len' = 'cp' first -- which will introduce * one or more undefined bytes. * * NB: the string is NOT re-terminated. + * + * NB: if this is a "dummy" qstring, a copy is made of the original body. */ Inline size_t qs_insert(qstring qs, const void* src, size_t n) @@ -308,15 +400,19 @@ qs_insert(qstring qs, const void* src, size_t n) * * May increase 'len'. but does not affect 'cp'. * + * NB: qstring MUST NOT be NULL + * * NB: if 'cp' > 'len', then sets 'len' = 'cp' first -- which will introduce * one or more undefined bytes. * * NB: the string is NOT re-terminated. + * + * NB: if this is a "dummy" qstring, a copy is made of the original body. */ Inline void qs_replace(qstring qs, const void* src, size_t n) { - if (qs->len < qs->cp + n) + if ((qs->len < qs->cp + n) || (qs->size == 0)) qs_set_len(qs, qs->cp + n) ; /* set len and ensure have space */ if (n > 0) @@ -330,6 +426,8 @@ qs_replace(qstring qs, const void* src, size_t n) * * Returns: number of bytes beyond 'cp' that were moved before insert. * + * NB: qstring MUST NOT be NULL + * * NB: if 'cp' > 'len', then sets 'len' = 'cp' first -- which will introduce * one or more undefined bytes. * @@ -341,6 +439,10 @@ qs_delete(qstring qs, size_t n) size_t after ; char* p ; + /* Watch out for "dummy" */ + if (qs->size == 0) + qs_make_to_length(qs, qs->len) ; + /* If deleting up to or beyond len, then simply set len == cp */ if ((qs->cp + n) >= qs->len) { @@ -362,4 +464,5 @@ qs_delete(qstring qs, size_t n) return after ; } ; + #endif /* _ZEBRA_QSTRING_H */ |