PostgreSQL Source Code: src/bin/pg_dump/pg_backup_null.c Source File

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pg_backup_null.c
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1/*-------------------------------------------------------------------------
2 *
3 * pg_backup_null.c
4 *
5 * Implementation of an archive that is never saved; it is used by
6 * pg_dump to output a plain text SQL script instead of saving
7 * a real archive.
8 *
9 * See the headers to pg_restore for more details.
10 *
11 * Copyright (c) 2000, Philip Warner
12 * Rights are granted to use this software in any way so long
13 * as this notice is not removed.
14 *
15 * The author is not responsible for loss or damages that may
16 * result from its use.
17 *
18 *
19 * IDENTIFICATION
20 * src/bin/pg_dump/pg_backup_null.c
21 *
22 *-------------------------------------------------------------------------
23 */
24#include "postgres_fe.h"
25
26#include "fe_utils/string_utils.h"
27#include "libpq/libpq-fs.h"
28#include "pg_backup_archiver.h"
29#include "pg_backup_utils.h"
30
31static void _WriteData(ArchiveHandle *AH, const void *data, size_t dLen);
32static void _WriteLOData(ArchiveHandle *AH, const void *data, size_t dLen);
33static void _EndData(ArchiveHandle *AH, TocEntry *te);
34static int _WriteByte(ArchiveHandle *AH, const int i);
35static void _WriteBuf(ArchiveHandle *AH, const void *buf, size_t len);
36static void _CloseArchive(ArchiveHandle *AH);
37static void _PrintTocData(ArchiveHandle *AH, TocEntry *te);
38static void _StartLOs(ArchiveHandle *AH, TocEntry *te);
39static void _StartLO(ArchiveHandle *AH, TocEntry *te, Oid oid);
40static void _EndLO(ArchiveHandle *AH, TocEntry *te, Oid oid);
41static void _EndLOs(ArchiveHandle *AH, TocEntry *te);
42
43
44/*
45 * Initializer
46 */
47void
48 InitArchiveFmt_Null(ArchiveHandle *AH)
49{
50 /* Assuming static functions, this can be copied for each format. */
51 AH->WriteDataPtr = _WriteData;
52 AH->EndDataPtr = _EndData;
53 AH->WriteBytePtr = _WriteByte;
54 AH->WriteBufPtr = _WriteBuf;
55 AH->ClosePtr = _CloseArchive;
56 AH->ReopenPtr = NULL;
57 AH->PrintTocDataPtr = _PrintTocData;
58
59 AH->StartLOsPtr = _StartLOs;
60 AH->StartLOPtr = _StartLO;
61 AH->EndLOPtr = _EndLO;
62 AH->EndLOsPtr = _EndLOs;
63 AH->ClonePtr = NULL;
64 AH->DeClonePtr = NULL;
65
66 /*
67 * Now prevent reading...
68 */
69 if (AH->mode == archModeRead)
70 pg_fatal("this format cannot be read");
71}
72
73/*
74 * - Start a new TOC entry
75 */
76
77/*
78 * Called by dumper via archiver from within a data dump routine
79 */
80static void
81 _WriteData(ArchiveHandle *AH, const void *data, size_t dLen)
82{
83 /* Just send it to output, ahwrite() already errors on failure */
84 ahwrite(data, 1, dLen, AH);
85}
86
87/*
88 * Called by dumper via archiver from within a data dump routine
89 * We substitute this for _WriteData while emitting a LO
90 */
91static void
92 _WriteLOData(ArchiveHandle *AH, const void *data, size_t dLen)
93{
94 if (dLen > 0)
95 {
96 PQExpBuffer buf = createPQExpBuffer();
97
98 appendByteaLiteralAHX(buf,
99 (const unsigned char *) data,
100 dLen,
101 AH);
102
103 ahprintf(AH, "SELECT pg_catalog.lowrite(0, %s);\n", buf->data);
104
105 destroyPQExpBuffer(buf);
106 }
107}
108
109static void
110 _EndData(ArchiveHandle *AH, TocEntry *te)
111{
112 ahprintf(AH, "\n\n");
113}
114
115/*
116 * Called by the archiver when starting to save BLOB DATA (not schema).
117 * This routine should save whatever format-specific information is needed
118 * to read the LOs back into memory.
119 *
120 * It is called just prior to the dumper's DataDumper routine.
121 *
122 * Optional, but strongly recommended.
123 */
124static void
125 _StartLOs(ArchiveHandle *AH, TocEntry *te)
126{
127 ahprintf(AH, "BEGIN;\n\n");
128}
129
130/*
131 * Called by the archiver when the dumper calls StartLO.
132 *
133 * Mandatory.
134 *
135 * Must save the passed OID for retrieval at restore-time.
136 */
137static void
138 _StartLO(ArchiveHandle *AH, TocEntry *te, Oid oid)
139{
140 bool old_lo_style = (AH->version < K_VERS_1_12);
141
142 if (oid == 0)
143 pg_fatal("invalid OID for large object");
144
145 /* With an old archive we must do drop and create logic here */
146 if (old_lo_style && AH->public.ropt->dropSchema)
147 DropLOIfExists(AH, oid);
148
149 if (old_lo_style)
150 ahprintf(AH, "SELECT pg_catalog.lo_open(pg_catalog.lo_create('%u'), %d);\n",
151 oid, INV_WRITE);
152 else
153 ahprintf(AH, "SELECT pg_catalog.lo_open('%u', %d);\n",
154 oid, INV_WRITE);
155
156 AH->WriteDataPtr = _WriteLOData;
157}
158
159/*
160 * Called by the archiver when the dumper calls EndLO.
161 *
162 * Optional.
163 */
164static void
165 _EndLO(ArchiveHandle *AH, TocEntry *te, Oid oid)
166{
167 AH->WriteDataPtr = _WriteData;
168
169 ahprintf(AH, "SELECT pg_catalog.lo_close(0);\n\n");
170}
171
172/*
173 * Called by the archiver when finishing saving BLOB DATA.
174 *
175 * Optional.
176 */
177static void
178 _EndLOs(ArchiveHandle *AH, TocEntry *te)
179{
180 ahprintf(AH, "COMMIT;\n\n");
181}
182
183/*------
184 * Called as part of a RestoreArchive call; for the NULL archive, this
185 * just sends the data for a given TOC entry to the output.
186 *------
187 */
188static void
189 _PrintTocData(ArchiveHandle *AH, TocEntry *te)
190{
191 if (te->dataDumper)
192 {
193 AH->currToc = te;
194
195 if (strcmp(te->desc, "BLOBS") == 0)
196 _StartLOs(AH, te);
197
198 te->dataDumper((Archive *) AH, te->dataDumperArg);
199
200 if (strcmp(te->desc, "BLOBS") == 0)
201 _EndLOs(AH, te);
202
203 AH->currToc = NULL;
204 }
205}
206
207static int
208 _WriteByte(ArchiveHandle *AH, const int i)
209{
210 /* Don't do anything */
211 return 0;
212}
213
214static void
215 _WriteBuf(ArchiveHandle *AH, const void *buf, size_t len)
216{
217 /* Don't do anything */
218}
219
220static void
221 _CloseArchive(ArchiveHandle *AH)
222{
223 /* Nothing to do */
224}
i
int i
Definition: isn.c:77
#define INV_WRITE
Definition: libpq-fs.h:21
@ archModeRead
Definition: pg_backup.h:52
void ahwrite(const void *ptr, size_t size, size_t nmemb, ArchiveHandle *AH)
int ahprintf(ArchiveHandle *AH, const char *fmt,...)
#define appendByteaLiteralAHX(buf, str, len, AH)
void DropLOIfExists(ArchiveHandle *AH, Oid oid)
Definition: pg_backup_db.c:612
#define K_VERS_1_12
static void _PrintTocData(ArchiveHandle *AH, TocEntry *te)
void InitArchiveFmt_Null(ArchiveHandle *AH)
Definition: pg_backup_null.c:48
static void _WriteData(ArchiveHandle *AH, const void *data, size_t dLen)
Definition: pg_backup_null.c:81
static void _CloseArchive(ArchiveHandle *AH)
static void _StartLOs(ArchiveHandle *AH, TocEntry *te)
static void _EndLO(ArchiveHandle *AH, TocEntry *te, Oid oid)
static void _EndLOs(ArchiveHandle *AH, TocEntry *te)
static int _WriteByte(ArchiveHandle *AH, const int i)
static void _StartLO(ArchiveHandle *AH, TocEntry *te, Oid oid)
static void _WriteLOData(ArchiveHandle *AH, const void *data, size_t dLen)
Definition: pg_backup_null.c:92
static void _EndData(ArchiveHandle *AH, TocEntry *te)
static void _WriteBuf(ArchiveHandle *AH, const void *buf, size_t len)
#define pg_fatal(...)
const void size_t len
const void * data
static char * buf
Definition: pg_test_fsync.c:72
unsigned int Oid
Definition: postgres_ext.h:32
PQExpBuffer createPQExpBuffer(void)
Definition: pqexpbuffer.c:72
void destroyPQExpBuffer(PQExpBuffer str)
Definition: pqexpbuffer.c:114
RestoreOptions * ropt
Definition: pg_backup.h:229
int version
DeClonePtrType DeClonePtr
EndLOsPtrType EndLOsPtr
ArchiveMode mode
StartLOsPtrType StartLOsPtr
WriteDataPtrType WriteDataPtr
StartLOPtrType StartLOPtr
ClonePtrType ClonePtr
WriteBufPtrType WriteBufPtr
EndLOPtrType EndLOPtr
PrintTocDataPtrType PrintTocDataPtr
struct _tocEntry * currToc
WriteBytePtrType WriteBytePtr
ReopenPtrType ReopenPtr
EndDataPtrType EndDataPtr
Archive public
ClosePtrType ClosePtr
int dropSchema
Definition: pg_backup.h:108
DataDumperPtr dataDumper
const void * dataDumperArg
char * desc

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