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enhanced qse_mbsxsubst() and qse_wcsxsubst() for buffer size prediction

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hyung-hwan
2013-09-09 05:47:54 +00:00
parent 88266f1b2e
commit 04e6df3dd8
3 changed files with 108 additions and 6 deletions
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83
qse/include/qse/cmn/str.h
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@ -125,6 +125,10 @@ struct qse_wcs_t
qse_size_t capa; /**< buffer capacity */
};
#define QSE_MBSSUBST_NOBUF ((qse_mchar_t*)1)
#define QSE_WCSSUBST_NOBUF ((qse_wchar_t*)1)
/**
* The qse_mbssubst_t type defines a callback function for qse_mbsxsubst()
* and qse_mbsxnsubst() to substitue a new value for an identifier \a ident.
@ -148,8 +152,10 @@ typedef qse_wchar_t* (*qse_wcssubst_t) (
);
#if defined(QSE_CHAR_IS_MCHAR)
# define QSE_STRSUBST_NOBUF QSE_MBSSUBST_NOBUF
# define qse_strsubst_t qse_mbssubst_t
#else
# define QSE_STRSUBST_NOBUF QSE_WCSSUBST_NOBUF
# define qse_strsubst_t qse_wcssubst_t
#endif
@ -696,6 +702,45 @@ QSE_EXPORT qse_size_t qse_wcsxfncpy (
* qse_mchar_t buf[25];
* qse_mbsxsubst (buf, i, QSE_MT("user=${USER},group=${GROUP}"), subst, QSE_NULL);
* \endcode
*
* If \a buf is #QSE_MBSSUBST_NOBUF, the function returns the length of the
* resulting string that a buffer large enough would be able to hold. You can
* pass #QSE_MBSSUBST_NOBUF to find out how large a buffer you need to perform
* substitution without truncation. The substitution callback function should
* handle this special case for buffer size prediction. The sample callback shown
* above can be extended to return the buffer pointer without actual copying
* if the buffer points to #QSE_MBSSUBST_NOBUF as shown belown.
*
* \code
* qse_mchar_t* subst (qse_mchar_t* buf, qse_size_t bsz, const qse_mcstr_t* ident, void* ctx)
* {
* if (qse_mcsxcmp (ident->ptr, ident->len, QSE_MT("USER")) == 0)
* return buf + (buf == QSE_MBSSUBST_NOBUF? 3: qse_mcsxput (buf, bsz, QSE_MT("sam")));
* else if (qse_mcsxcmp (ident->ptr, ident->len, QSE_MT("GROUP")) == 0)
* return buf + (buf == QSE_MBSSUBST_NOBUF? 6: qse_mcsxput (buf, bsz, QSE_MT("coders")));
* return buf;
* }
*
* len = qse_mbsxsubst (QSE_MBSSUBST_NOBUF, 0, QSE_MT("user=${USER},group=${GROUP}"), subst, QSE_NULL);
* buf = malloc (QSE_SIZEOF(qse_mbs_t) * (len + 1));
* qse_mbsxsubst (buf, len + 1, QSE_MT("user=${USER},group=${GROUP}"), subst, QSE_NULL);
* \endcode
*
* A ${} segment may contain a default value. For example, the segment
* ${USER:=Unknown} translates to Unknown if the callback function returns
* #QSE_NULL for USER. The default value part may contain ${} segments
* recursively.
*
* \code
* qse_mchar_t* subst (qse_mchar_t* buf, qse_size_t bsz, const qse_mcstr_t* ident, void* ctx)
* {
* if (qse_mbsxcmp (ident->ptr, ident->len, QSE_MT("USER")) == 0)
* return QSE_NULL;
* else if (qse_mbsxcmp (ident->ptr, ident->len, QSE_MT("GROUP")) == 0)
* return buf + (buf == QSE_MBSSUBST_NOBUF? 6: qse_wcsxput (buf, bsz, QSE_MT("coders")));
* return buf;
* }
* \endcode
*/
QSE_EXPORT qse_size_t qse_mbsxsubst (
qse_mchar_t* buf,
@ -731,6 +776,44 @@ QSE_EXPORT qse_size_t qse_mbsxnsubst (
* qse_wchar_t buf[25];
* qse_wcsxsubst (buf, i, QSE_WT("user=${USER},group=${GROUP}"), subst, QSE_NULL);
* \endcode
*
* If \a buf is #QSE_WCSSUBST_NOBUF, the function returns the length of the
* resulting string that a buffer large enough would be able to hold. You can
* pass #QSE_WCSSUBST_NOBUF to find out how large a buffer you need to perform
* substitution without truncation. The substitution callback function should
* handle this special case for buffer size prediction. The sample callback shown
* above can be extended to return the buffer pointer without actual copying
*
* \code
* qse_mchar_t* subst (qse_mchar_t* buf, qse_size_t bsz, const qse_wcstr_t* ident, void* ctx)
* {
* if (qse_wcsxcmp (ident->ptr, ident->len, QSE_WT("USER")) == 0)
* return buf + (buf == QSE_WCSSUBST_NOBUF? 3: qse_wcsxput (buf, bsz, QSE_WT("sam")));
* else if (qse_wcsxcmp (ident->ptr, ident->len, QSE_WT("GROUP")) == 0)
* return buf + (buf == QSE_WCSSUBST_NOBUF? 6: qse_wcsxput (buf, bsz, QSE_WT("coders")));
* return buf;
* }
*
* len = qse_wcsxsubst (QSE_WCSSUBST_NOBUF, 0, QSE_WT("user=${USER},group=${GROUP}"), subst, QSE_NULL);
* buf = malloc (QSE_SIZEOF(qse_wcs_t) * (len + 1));
* qse_wcsxsubst (buf, len + 1, QSE_WT("user=${USER},group=${GROUP}"), subst, QSE_NULL);
* \endcode
*
* A ${} segment may contain a default value. For example, the segment
* ${USER:=Unknown} translates to Unknown if the callback function returns
* #QSE_NULL for USER. The default value part may contain ${} segments
* recursively.
*
* \code
* qse_mchar_t* subst (qse_mchar_t* buf, qse_size_t bsz, const qse_wcstr_t* ident, void* ctx)
* {
* if (qse_wcsxcmp (ident->ptr, ident->len, QSE_WT("USER")) == 0)
* return QSE_NULL;
* else if (qse_wcsxcmp (ident->ptr, ident->len, QSE_WT("GROUP")) == 0)
* return buf + (buf == QSE_WCSSUBST_NOBUF? 6: qse_wcsxput (buf, bsz, QSE_WT("coders")));
* return buf;
* }
* \endcode
*/
QSE_EXPORT qse_size_t qse_wcsxsubst (
qse_wchar_t* buf,