mirror of https://github.com/postgres/postgres
This enables non-backend code, such as pg_xlogdump, to use it easily. The previous location, in src/backend/catalog/catalog.c, made that essentially impossible because that file depends on many backend-only facilities; so this needs to live separately.pull/3/head
Alvaro Herrera
13 years ago
parent
6e3fd96463
commit
a730183926
@ -0,0 +1,162 @@ |
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/*-------------------------------------------------------------------------
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* relpath.c |
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* Shared frontend/backend code to find out pathnames of relation files |
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* |
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* Portions Copyright (c) 1996-2013, PostgreSQL Global Development Group |
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* Portions Copyright (c) 1994, Regents of the University of California |
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* |
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* IDENTIFICATION |
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* src/common/relpath.c |
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* |
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*------------------------------------------------------------------------- |
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*/ |
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#ifndef FRONTEND |
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#include "postgres.h" |
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#else |
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#include "postgres_fe.h" |
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#endif |
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#include "catalog/pg_tablespace.h" |
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#include "common/relpath.h" |
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#include "storage/backendid.h" |
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#define FORKNAMECHARS 4 /* max chars for a fork name */ |
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/*
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* Lookup table of fork name by fork number. |
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* |
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* If you add a new entry, remember to update the errhint below, and the |
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* documentation for pg_relation_size(). Also keep FORKNAMECHARS above |
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* up-to-date. |
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*/ |
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const char *forkNames[] = { |
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"main", /* MAIN_FORKNUM */ |
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"fsm", /* FSM_FORKNUM */ |
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"vm", /* VISIBILITYMAP_FORKNUM */ |
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"init" /* INIT_FORKNUM */ |
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}; |
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|
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/*
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* forkname_chars |
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* We use this to figure out whether a filename could be a relation |
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* fork (as opposed to an oddly named stray file that somehow ended |
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* up in the database directory). If the passed string begins with |
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* a fork name (other than the main fork name), we return its length, |
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* and set *fork (if not NULL) to the fork number. If not, we return 0. |
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* |
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* Note that the present coding assumes that there are no fork names which |
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* are prefixes of other fork names. |
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*/ |
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int |
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forkname_chars(const char *str, ForkNumber *fork) |
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{ |
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ForkNumber forkNum; |
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for (forkNum = 1; forkNum <= MAX_FORKNUM; forkNum++) |
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{ |
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int len = strlen(forkNames[forkNum]); |
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if (strncmp(forkNames[forkNum], str, len) == 0) |
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{ |
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if (fork) |
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*fork = forkNum; |
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return len; |
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} |
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} |
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return 0; |
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} |
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/*
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* relpathbackend - construct path to a relation's file |
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* |
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* Result is a palloc'd string. |
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*/ |
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char * |
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relpathbackend(RelFileNode rnode, BackendId backend, ForkNumber forknum) |
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{ |
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int pathlen; |
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char *path; |
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if (rnode.spcNode == GLOBALTABLESPACE_OID) |
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{ |
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/* Shared system relations live in {datadir}/global */ |
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Assert(rnode.dbNode == 0); |
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Assert(backend == InvalidBackendId); |
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pathlen = 7 + OIDCHARS + 1 + FORKNAMECHARS + 1; |
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path = (char *) palloc(pathlen); |
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if (forknum != MAIN_FORKNUM) |
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snprintf(path, pathlen, "global/%u_%s", |
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rnode.relNode, forkNames[forknum]); |
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else |
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snprintf(path, pathlen, "global/%u", rnode.relNode); |
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} |
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else if (rnode.spcNode == DEFAULTTABLESPACE_OID) |
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{ |
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/* The default tablespace is {datadir}/base */ |
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if (backend == InvalidBackendId) |
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{ |
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pathlen = 5 + OIDCHARS + 1 + OIDCHARS + 1 + FORKNAMECHARS + 1; |
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path = (char *) palloc(pathlen); |
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if (forknum != MAIN_FORKNUM) |
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snprintf(path, pathlen, "base/%u/%u_%s", |
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rnode.dbNode, rnode.relNode, |
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forkNames[forknum]); |
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else |
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snprintf(path, pathlen, "base/%u/%u", |
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rnode.dbNode, rnode.relNode); |
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} |
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else |
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{ |
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/* OIDCHARS will suffice for an integer, too */ |
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pathlen = 5 + OIDCHARS + 2 + OIDCHARS + 1 + OIDCHARS + 1 |
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+ FORKNAMECHARS + 1; |
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path = (char *) palloc(pathlen); |
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if (forknum != MAIN_FORKNUM) |
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snprintf(path, pathlen, "base/%u/t%d_%u_%s", |
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rnode.dbNode, backend, rnode.relNode, |
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forkNames[forknum]); |
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else |
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snprintf(path, pathlen, "base/%u/t%d_%u", |
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rnode.dbNode, backend, rnode.relNode); |
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} |
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} |
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else |
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{ |
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/* All other tablespaces are accessed via symlinks */ |
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if (backend == InvalidBackendId) |
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{ |
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pathlen = 9 + 1 + OIDCHARS + 1 |
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+ strlen(TABLESPACE_VERSION_DIRECTORY) + 1 + OIDCHARS + 1 |
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+ OIDCHARS + 1 + FORKNAMECHARS + 1; |
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path = (char *) palloc(pathlen); |
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if (forknum != MAIN_FORKNUM) |
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snprintf(path, pathlen, "pg_tblspc/%u/%s/%u/%u_%s", |
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rnode.spcNode, TABLESPACE_VERSION_DIRECTORY, |
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rnode.dbNode, rnode.relNode, |
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forkNames[forknum]); |
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else |
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snprintf(path, pathlen, "pg_tblspc/%u/%s/%u/%u", |
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rnode.spcNode, TABLESPACE_VERSION_DIRECTORY, |
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rnode.dbNode, rnode.relNode); |
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} |
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else |
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{ |
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/* OIDCHARS will suffice for an integer, too */ |
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pathlen = 9 + 1 + OIDCHARS + 1 |
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+ strlen(TABLESPACE_VERSION_DIRECTORY) + 1 + OIDCHARS + 2 |
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+ OIDCHARS + 1 + OIDCHARS + 1 + FORKNAMECHARS + 1; |
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path = (char *) palloc(pathlen); |
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if (forknum != MAIN_FORKNUM) |
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snprintf(path, pathlen, "pg_tblspc/%u/%s/%u/t%d_%u_%s", |
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rnode.spcNode, TABLESPACE_VERSION_DIRECTORY, |
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rnode.dbNode, backend, rnode.relNode, |
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forkNames[forknum]); |
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else |
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snprintf(path, pathlen, "pg_tblspc/%u/%s/%u/t%d_%u", |
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rnode.spcNode, TABLESPACE_VERSION_DIRECTORY, |
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rnode.dbNode, backend, rnode.relNode); |
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} |
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} |
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return path; |
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} |
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@ -0,0 +1,41 @@ |
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/*-------------------------------------------------------------------------
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* |
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* relpath.h |
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* Declarations for relpath() and friends |
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* |
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* Portions Copyright (c) 1996-2013, PostgreSQL Global Development Group |
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* Portions Copyright (c) 1994, Regents of the University of California |
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* |
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* src/include/common/relpath.h |
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* |
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*------------------------------------------------------------------------- |
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*/ |
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#ifndef RELPATH_H |
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#define RELPATH_H |
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/*
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* 'pgrminclude ignore' needed here because CppAsString2() does not throw |
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* an error if the symbol is not defined. |
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*/ |
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#include "catalog/catversion.h" /* pgrminclude ignore */ |
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#include "storage/relfilenode.h" |
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#define OIDCHARS 10 /* max chars printed by %u */ |
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#define TABLESPACE_VERSION_DIRECTORY "PG_" PG_MAJORVERSION "_" \ |
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CppAsString2(CATALOG_VERSION_NO) |
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extern const char *forkNames[]; |
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extern int forkname_chars(const char *str, ForkNumber *fork); |
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extern char *relpathbackend(RelFileNode rnode, BackendId backend, |
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ForkNumber forknum); |
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/* First argument is a RelFileNodeBackend */ |
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#define relpath(rnode, forknum) \ |
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relpathbackend((rnode).node, (rnode).backend, (forknum)) |
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/* First argument is a RelFileNode */ |
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#define relpathperm(rnode, forknum) \ |
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relpathbackend((rnode), InvalidBackendId, (forknum)) |
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#endif /* RELPATH_H */ |
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