diff options
Diffstat (limited to 'src/backend/nodes/read.c')
| -rw-r--r-- | src/backend/nodes/read.c | 58 |
1 files changed, 33 insertions, 25 deletions
diff --git a/src/backend/nodes/read.c b/src/backend/nodes/read.c index df8fcb876d6..1bfc6f7c534 100644 --- a/src/backend/nodes/read.c +++ b/src/backend/nodes/read.c @@ -9,7 +9,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/nodes/read.c,v 1.26 2000/12/03 20:45:33 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/nodes/read.c,v 1.27 2001/01/07 01:08:47 tgl Exp $ * * HISTORY * AUTHOR DATE MAJOR EVENT @@ -25,6 +25,11 @@ #include "nodes/pg_list.h" #include "nodes/readfuncs.h" + +/* Static state for pg_strtok */ +static char *pg_strtok_ptr = NULL; + + /* * stringToNode - * returns a Node with a given legal ASCII representation @@ -32,10 +37,22 @@ void * stringToNode(char *str) { + char *save_strtok; void *retval; - lsptok(str, NULL); /* set the string used in lsptok */ - retval = nodeRead(true); /* start reading */ + /* + * We save and restore the pre-existing state of pg_strtok. + * This makes the world safe for re-entrant invocation of stringToNode, + * without incurring a lot of notational overhead by having to pass the + * next-character pointer around through all the readfuncs.c code. + */ + save_strtok = pg_strtok_ptr; + + pg_strtok_ptr = str; /* point pg_strtok at the string to read */ + + retval = nodeRead(true); /* do the reading */ + + pg_strtok_ptr = save_strtok; return retval; } @@ -47,7 +64,7 @@ stringToNode(char *str) *****************************************************************************/ /* - * lsptok --- retrieve next "token" from a string. + * pg_strtok --- retrieve next "token" from a string. * * Works kinda like strtok, except it never modifies the source string. * (Instead of storing nulls into the string, the length of the token @@ -55,9 +72,7 @@ stringToNode(char *str) * Also, the rules about what is a token are hard-wired rather than being * configured by passing a set of terminating characters. * - * The string is initially set by passing a non-NULL "string" value, - * and subsequent calls with string==NULL read the previously given value. - * (Pass length==NULL to set the string without reading its first token.) + * The string is assumed to have been initialized already by stringToNode. * * The rules for tokens are: * * Whitespace (space, tab, newline) always separates tokens. @@ -89,20 +104,12 @@ stringToNode(char *str) * as a single token. */ char * -lsptok(char *string, int *length) +pg_strtok(int *length) { - static char *saved_str = NULL; char *local_str; /* working pointer to string */ char *ret_str; /* start of token to return */ - if (string != NULL) - { - saved_str = string; - if (length == NULL) - return NULL; - } - - local_str = saved_str; + local_str = pg_strtok_ptr; while (*local_str == ' ' || *local_str == '\n' || *local_str == '\t') local_str++; @@ -110,7 +117,7 @@ lsptok(char *string, int *length) if (*local_str == '\0') { *length = 0; - saved_str = local_str; + pg_strtok_ptr = local_str; return NULL; /* no more tokens */ } @@ -147,7 +154,7 @@ lsptok(char *string, int *length) if (*length == 2 && ret_str[0] == '<' && ret_str[1] == '>') *length = 0; - saved_str = local_str; + pg_strtok_ptr = local_str; return ret_str; } @@ -223,7 +230,7 @@ nodeTokenType(char *token, int length) } /* - * these three cases do not need length checks, since lsptok() will + * these three cases do not need length checks, since pg_strtok() will * always treat them as single-byte tokens */ else if (*token == '(') @@ -248,12 +255,13 @@ nodeTokenType(char *token, int length) * Slightly higher-level reader. * * This routine applies some semantic knowledge on top of the purely - * lexical tokenizer lsptok(). It can read + * lexical tokenizer pg_strtok(). It can read * * Value token nodes (integers, floats, or strings); * * Plan nodes (via parsePlanString() from readfuncs.c); * * Lists of the above. * - * Secrets: He assumes that lsptok already has the string (see above). + * We assume pg_strtok is already initialized with a string to read (hence + * this should only be invoked from within a stringToNode operation). * Any callers should set read_car_only to true. */ void * @@ -266,7 +274,7 @@ nodeRead(bool read_car_only) *return_value; bool make_dotted_pair_cell = false; - token = lsptok(NULL, &tok_len); + token = pg_strtok(&tok_len); if (token == NULL) return NULL; @@ -277,8 +285,8 @@ nodeRead(bool read_car_only) { case PLAN_SYM: this_value = parsePlanString(); - token = lsptok(NULL, &tok_len); - if (token[0] != '}') + token = pg_strtok(&tok_len); + if (token == NULL || token[0] != '}') elog(ERROR, "nodeRead: did not find '}' at end of plan node"); if (!read_car_only) make_dotted_pair_cell = true; |