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Back-patch fix for extraction of fixed prefixes from regular expressions.

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Back-patch of commits 628cbb50ba and
c6aae3042b.  This has been broken since
7.3, so back-patch to all supported branches.
This commit is contained in:
Tom Lane
2012-07-10 18:00:51 -04:00
parent b84da909d9
commit b9edaa784e
11 changed files with 429 additions and 208 deletions
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30
src/include/regex/regguts.h
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@ -188,6 +188,7 @@ struct colordesc
color sub; /* open subcolor (if any); free chain ptr */
#define NOSUB COLORLESS
struct arc *arcs; /* color chain */
chr firstchr; /* char first assigned to this color */
int flags;
#define FREECOL 01 /* currently free */
#define PSEUDO 02 /* pseudocolor, no real chars */
@ -255,15 +256,14 @@ struct state;
struct arc
{
int type;
#define ARCFREE '\0'
int type; /* 0 if free, else an NFA arc type code */
color co;
struct state *from; /* where it's from (and contained within) */
struct state *to; /* where it's to */
struct arc *outchain; /* *from's outs chain or free chain */
struct arc *outchain; /* link in *from's outs chain or free chain */
#define freechain outchain
struct arc *inchain; /* *to's ins chain */
struct arc *colorchain; /* color's arc chain */
struct arc *inchain; /* link in *to's ins chain */
struct arc *colorchain; /* link in color's arc chain */
struct arc *colorchainRev; /* back-link in color's arc chain */
};
@ -315,24 +315,38 @@ struct nfa
/*
* definitions for compacted NFA
*
* The main space savings in a compacted NFA is from making the arcs as small
* as possible. We store only the transition color and next-state number for
* each arc. The list of out arcs for each state is an array beginning at
* cnfa.states[statenumber], and terminated by a dummy carc struct with
* co == COLORLESS.
*
* The non-dummy carc structs are of two types: plain arcs and LACON arcs.
* Plain arcs just store the transition color number as "co". LACON arcs
* store the lookahead constraint number plus cnfa.ncolors as "co". LACON
* arcs can be distinguished from plain by testing for co >= cnfa.ncolors.
*/
struct carc
{
color co; /* COLORLESS is list terminator */
int to; /* state number */
int to; /* next-state number */
};
struct cnfa
{
int nstates; /* number of states */
int ncolors; /* number of colors */
int ncolors; /* number of colors (max color in use + 1) */
int flags;
#define HASLACONS 01 /* uses lookahead constraints */
#define HASLACONS 01 /* uses lookahead constraints */
int pre; /* setup state number */
int post; /* teardown state number */
color bos[2]; /* colors, if any, assigned to BOS and BOL */
color eos[2]; /* colors, if any, assigned to EOS and EOL */
char *stflags; /* vector of per-state flags bytes */
#define CNFA_NOPROGRESS 01 /* flag bit for a no-progress state */
struct carc **states; /* vector of pointers to outarc lists */
/* states[n] are pointers into a single malloc'd array of arcs */
struct carc *arcs; /* the area for the lists */
};