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Rewrite nodeRead() in a less obfuscated fashion, per discussion with

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Neil Conway.
REL8_0_STABLE
Tom Lane 22 years ago
parent 839be02ee1
commit eee6f9d5c2
4 changed files with 56 additions and 84 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
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  1. 3
      src/backend/nodes/outfuncs.c
  2. 125
      src/backend/nodes/read.c
  3. 8
      src/backend/nodes/readfuncs.c
  4. 4
      src/include/nodes/readfuncs.h

3
src/backend/nodes/outfuncs.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.233 2004/03/17 20:48:42 tgl Exp $
* $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.234 2004/05/06 14:01:33 tgl Exp $
*
* NOTES
* Every node type that can appear in stored rules' parsetrees *must*
@ -130,7 +130,6 @@ _outToken(StringInfo str, char *s)
/* These characters only need to be quoted at the start of the string */
if (*s == '<' ||
*s == '\"' ||
*s == '@' ||
isdigit((unsigned char) *s) ||
((*s == '+' || *s == '-') &&
(isdigit((unsigned char) s[1]) || s[1] == '.')))

125
src/backend/nodes/read.c
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@ -9,7 +9,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/nodes/read.c,v 1.39 2004/01/09 03:07:32 momjian Exp $
* $PostgreSQL: pgsql/src/backend/nodes/read.c,v 1.40 2004/05/06 14:01:33 tgl Exp $
*
* HISTORY
* AUTHOR DATE MAJOR EVENT
@ -20,7 +20,6 @@
#include "postgres.h"
#include <ctype.h>
#include <errno.h>
#include "nodes/pg_list.h"
#include "nodes/readfuncs.h"
@ -51,7 +50,7 @@ stringToNode(char *str)
pg_strtok_ptr = str; /* point pg_strtok at the string to read */
retval = nodeRead(true); /* do the reading */
retval = nodeRead(NULL, 0); /* do the reading */
pg_strtok_ptr = save_strtok;
@ -184,9 +183,8 @@ debackslash(char *token, int length)
#define RIGHT_PAREN (1000000 + 1)
#define LEFT_PAREN (1000000 + 2)
#define NODE_SYM (1000000 + 3)
#define AT_SYMBOL (1000000 + 4)
#define ATOM_TOKEN (1000000 + 5)
#define LEFT_BRACE (1000000 + 3)
#define OTHER_TOKEN (1000000 + 4)
/*
* nodeTokenType -
@ -194,7 +192,7 @@ debackslash(char *token, int length)
* It returns one of the following valid NodeTags:
* T_Integer, T_Float, T_String, T_BitString
* and some of its own:
* RIGHT_PAREN, LEFT_PAREN, NODE_SYM, AT_SYMBOL, ATOM_TOKEN
* RIGHT_PAREN, LEFT_PAREN, LEFT_BRACE, OTHER_TOKEN
*
* Assumption: the ascii representation is legal
*/
@ -245,15 +243,13 @@ nodeTokenType(char *token, int length)
else if (*token == ')')
retval = RIGHT_PAREN;
else if (*token == '{')
retval = NODE_SYM;
else if (*token == '@' && length == 1)
retval = AT_SYMBOL;
retval = LEFT_BRACE;
else if (*token == '\"' && length > 1 && token[length - 1] == '\"')
retval = T_String;
else if (*token == 'b')
retval = T_BitString;
else
retval = ATOM_TOKEN;
retval = OTHER_TOKEN;
return retval;
}
@ -266,77 +262,70 @@ nodeTokenType(char *token, int length)
* * Value token nodes (integers, floats, or strings);
* * General nodes (via parseNodeString() from readfuncs.c);
* * Lists of the above.
* The return value is declared void *, not Node *, to avoid having to
* cast it explicitly in callers that assign to fields of different types.
*
* External callers should always pass NULL/0 for the arguments. Internally
* a non-NULL token may be passed when the upper recursion level has already
* scanned the first token of a node's representation.
*
* 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 *
nodeRead(bool read_car_only)
nodeRead(char *token, int tok_len)
{
char *token;
int tok_len;
Node *result;
NodeTag type;
Node *this_value,
*return_value;
bool make_dotted_pair_cell = false;
token = pg_strtok(&tok_len);
if (token == NULL) /* need to read a token? */
{
token = pg_strtok(&tok_len);
if (token == NULL)
return NULL;
if (token == NULL) /* end of input */
return NULL;
}
type = nodeTokenType(token, tok_len);
switch (type)
{
case NODE_SYM:
this_value = parseNodeString();
case LEFT_BRACE:
result = parseNodeString();
token = pg_strtok(&tok_len);
if (token == NULL || token[0] != '}')
elog(ERROR, "did not find '}' at end of input node");
if (!read_car_only)
make_dotted_pair_cell = true;
else
make_dotted_pair_cell = false;
break;
case LEFT_PAREN:
if (!read_car_only)
{
List *l = makeNode(List);
lfirst(l) = nodeRead(false);
lnext(l) = nodeRead(false);
this_value = (Node *) l;
List *l = NIL;
for (;;)
{
token = pg_strtok(&tok_len);
if (token == NULL)
elog(ERROR, "unterminated List structure");
if (token[0] == ')')
break;
l = lappend(l, nodeRead(token, tok_len));
}
result = (Node *) l;
break;
}
else
this_value = nodeRead(false);
break;
case RIGHT_PAREN:
this_value = NULL;
break;
case AT_SYMBOL:
this_value = NULL;
elog(ERROR, "unexpected right parenthesis");
result = NULL; /* keep compiler happy */
break;
case ATOM_TOKEN:
case OTHER_TOKEN:
if (tok_len == 0)
{
/* must be "<>" */
this_value = NULL;
/*
* It might be NULL but it is an atom!
*/
if (read_car_only)
make_dotted_pair_cell = false;
else
make_dotted_pair_cell = true;
/* must be "<>" --- represents a null pointer */
result = NULL;
}
else
{
/* !attention! result is not a Node. Use with caution. */
this_value = (Node *) debackslash(token, tok_len);
make_dotted_pair_cell = true;
elog(ERROR, "unrecognized token: \"%.*s\"", tok_len, token);
result = NULL; /* keep compiler happy */
}
break;
case T_Integer:
@ -345,8 +334,7 @@ nodeRead(bool read_car_only)
* we know that the token terminates on a char atol will stop
* at
*/
this_value = (Node *) makeInteger(atol(token));
make_dotted_pair_cell = true;
result = (Node *) makeInteger(atol(token));
break;
case T_Float:
{
@ -354,14 +342,12 @@ nodeRead(bool read_car_only)
memcpy(fval, token, tok_len);
fval[tok_len] = '\0';
this_value = (Node *) makeFloat(fval);
make_dotted_pair_cell = true;
result = (Node *) makeFloat(fval);
}
break;
case T_String:
/* need to remove leading and trailing quotes, and backslashes */
this_value = (Node *) makeString(debackslash(token + 1, tok_len - 2));
make_dotted_pair_cell = true;
result = (Node *) makeString(debackslash(token + 1, tok_len - 2));
break;
case T_BitString:
{
@ -370,27 +356,14 @@ nodeRead(bool read_car_only)
/* skip leading 'b' */
strncpy(val, token + 1, tok_len - 1);
val[tok_len - 1] = '\0';
this_value = (Node *) makeBitString(val);
result = (Node *) makeBitString(val);
break;
}
default:
elog(ERROR, "unrecognized node type: %d", (int) type);
this_value = NULL; /* keep compiler happy */
result = NULL; /* keep compiler happy */
break;
}
if (make_dotted_pair_cell)
{
List *l = makeNode(List);
lfirst(l) = this_value;
if (!read_car_only)
lnext(l) = nodeRead(false);
else
lnext(l) = NULL;
return_value = (Node *) l;
}
else
return_value = this_value;
return return_value;
return (void *) result;
}

8
src/backend/nodes/readfuncs.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/nodes/readfuncs.c,v 1.166 2004/03/17 20:48:42 tgl Exp $
* $PostgreSQL: pgsql/src/backend/nodes/readfuncs.c,v 1.167 2004/05/06 14:01:33 tgl Exp $
*
* NOTES
* Path and Plan nodes do not have any readfuncs support, because we
@ -99,17 +99,17 @@
/* Read a Node field */
#define READ_NODE_FIELD(fldname) \
token = pg_strtok(&length); /* skip :fldname */ \
local_node->fldname = nodeRead(true)
local_node->fldname = nodeRead(NULL, 0)
/* Read an integer-list field */
#define READ_INTLIST_FIELD(fldname) \
token = pg_strtok(&length); /* skip :fldname */ \
local_node->fldname = toIntList(nodeRead(true))
local_node->fldname = toIntList(nodeRead(NULL, 0))
/* Read an OID-list field */
#define READ_OIDLIST_FIELD(fldname) \
token = pg_strtok(&length); /* skip :fldname */ \
local_node->fldname = toOidList(nodeRead(true))
local_node->fldname = toOidList(nodeRead(NULL, 0))
/* Routine exit */
#define READ_DONE() \

4
src/include/nodes/readfuncs.h
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@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/nodes/readfuncs.h,v 1.18 2003/11/29 22:41:06 pgsql Exp $
* $PostgreSQL: pgsql/src/include/nodes/readfuncs.h,v 1.19 2004/05/06 14:01:33 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -21,7 +21,7 @@
*/
extern char *pg_strtok(int *length);
extern char *debackslash(char *token, int length);
extern void *nodeRead(bool read_car_only);
extern void *nodeRead(char *token, int tok_len);
/*
* prototypes for functions in readfuncs.c

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