kwlookup.h File Reference

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Data Structures
struct	ScanKeywordList

Typedefs
typedef int(*	ScanKeywordHashFunc) (const void *key, size_t keylen)
typedef struct ScanKeywordList	ScanKeywordList

Functions
int	ScanKeywordLookup (const char *str, const ScanKeywordList *keywords)
static const char *	GetScanKeyword (int n, const ScanKeywordList *keywords)

Typedef Documentation

ScanKeywordHashFunc

typedef int(* ScanKeywordHashFunc) (const void *key, size_t keylen)

Definition at line 18 of file kwlookup.h.

ScanKeywordList

typedef struct ScanKeywordList ScanKeywordList

Function Documentation

GetScanKeyword()

static const char * GetScanKeyword ( int  n, const ScanKeywordList *  keywords  )

inlinestatic

Definition at line 39 of file kwlookup.h.

{
    return keywords->kw_string + keywords->kw_offsets[n];
}

References keywords.

Referenced by pg_get_keywords(), plpgsql_yylex(), ScanCKeywordLookup(), and ScanKeywordLookup().

ScanKeywordLookup()

int ScanKeywordLookup	(	const char *	str,
		const ScanKeywordList *	keywords
	)

Definition at line 38 of file kwlookup.c.

{
    size_t      len;
    int         h;
    const char *kw;
 
    /*
     * Reject immediately if too long to be any keyword.  This saves useless
     * hashing and downcasing work on long strings.
     */
    len = strlen(str);
    if (len > keywords->max_kw_len)
        return -1;
 
    /*
     * Compute the hash function.  We assume it was generated to produce
     * case-insensitive results.  Since it's a perfect hash, we need only
     * match to the specific keyword it identifies.
     */
    h = keywords->hash(str, len);
 
    /* An out-of-range result implies no match */
    if (h < 0 || h >= keywords->num_keywords)
        return -1;
 
    /*
     * Compare character-by-character to see if we have a match, applying an
     * ASCII-only downcasing to the input characters.  We must not use
     * tolower() since it may produce the wrong translation in some locales
     * (eg, Turkish).
     */
    kw = GetScanKeyword(h, keywords);
    while (*str != '\0')
    {
        char        ch = *str++;
 
        if (ch >= 'A' && ch <= 'Z')
            ch += 'a' - 'A';
        if (ch != *kw++)
            return -1;
    }
    if (*kw != '\0')
        return -1;
 
    /* Success! */
    return h;
}

References GetScanKeyword(), keywords, len, and str.

Referenced by fmtIdEnc(), plpgsql_yylex(), quote_identifier(), and ScanECPGKeywordLookup().