PostgreSQL的 initdb 源代码分析之十三
继续分析：
/* Bootstrap template1 */ bootstrap_template1();
展开：
我这里读入的文件是：/home/pgsql/project/share/postgres.bki
/* * run the BKI script in bootstrap mode to create template1 */ static void bootstrap_template1(void) { PG_CMD_DECL; char **line; char *talkargs = ""; char **bki_lines; char headerline[MAXPGPATH]; char buf[64]; printf(_("creating template1 database in %s/base/1 ... "), pg_data); fflush(stdout); if (debug) talkargs = "-d 5"; bki_lines = readfile(bki_file); /* Check that bki file appears to be of the right version */ snprintf(headerline, sizeof(headerline), "# PostgreSQL %s\n", PG_MAJORVERSION); if (strcmp(headerline, *bki_lines) != 0) { fprintf(stderr, _("%s: input file \"%s\" does not belong to PostgreSQL %s\n" "Check your installation or specify the correct path " "using the option -L.\n"), progname, bki_file, PG_VERSION); exit_nicely(); } /* Substitute for various symbols used in the BKI file */ sprintf(buf, "%d", NAMEDATALEN); bki_lines = replace_token(bki_lines, "NAMEDATALEN", buf); sprintf(buf, "%d", (int) sizeof(Pointer)); bki_lines = replace_token(bki_lines, "SIZEOF_POINTER", buf); bki_lines = replace_token(bki_lines, "ALIGNOF_POINTER", (sizeof(Pointer) == 4) ? "i" : "d"); bki_lines = replace_token(bki_lines, "FLOAT4PASSBYVAL", FLOAT4PASSBYVAL ? "true" : "false"); bki_lines = replace_token(bki_lines, "FLOAT8PASSBYVAL", FLOAT8PASSBYVAL ? "true" : "false"); bki_lines = replace_token(bki_lines, "POSTGRES", username); bki_lines = replace_token(bki_lines, "ENCODING", encodingid); bki_lines = replace_token(bki_lines, "LC_COLLATE", escape_quotes(lc_collate)); bki_lines = replace_token(bki_lines, "LC_CTYPE", escape_quotes(lc_ctype)); /* * Pass correct LC_xxx environment to bootstrap. * * The shell script arranged to restore the LC settings afterwards, but * there doesn't seem to be any compelling reason to do that. */ snprintf(cmd, sizeof(cmd), "LC_COLLATE=%s", lc_collate); putenv(xstrdup(cmd)); snprintf(cmd, sizeof(cmd), "LC_CTYPE=%s", lc_ctype); putenv(xstrdup(cmd)); unsetenv("LC_ALL"); /* Also ensure backend isn't confused by this environment var: */ unsetenv("PGCLIENTENCODING"); snprintf(cmd, sizeof(cmd), "\"%s\" --boot -x1 %s %s", backend_exec, boot_options, talkargs); PG_CMD_OPEN; for (line = bki_lines; *line != NULL; line++) { PG_CMD_PUTS(*line); free(*line); } PG_CMD_CLOSE; free(bki_lines); check_ok(); }
其中， bki_lines = readfile(bki_file) ，是得到了要读取的文件的每一行。
再展开看 replace_token 函数：
这个函数就是用 replacement指向的字符串，替换在 lines所代表的文件内容行数组中所有token值。
比如：
sprintf(buf, "%d", NAMEDATALEN);
bki_lines = replace_token(bki_lines, "NAMEDATALEN", buf);
把 postgres.bki 文件中 类似于
insert OID = 19 ( name 11 10 NAMEDATALEN f b S f t \054 0 18 1003 namein nameout namerecv namesend - - - c p f 0 -1 0 0 _null_ _null_ )
这样的句子，在内存中替换为（根据宏定义、NAMEDATALEN为64）：
insert OID = 19 ( name 11 10 64 f b S f t \054 0 18 1003 namein nameout namerecv namesend - - - c p f 0 -1 0 0 _null_ _null_ )
/* * make a copy of the array of lines, with token replaced by replacement * the first time it occurs on each line. * * This does most of what sed was used for in the shell script, but * doesn't need any regexp stuff. */ static char ** replace_token(char **lines, const char *token, const char *replacement) { int numlines = 1; int i; char **result; int toklen, replen, diff; for (i = 0; lines[i]; i++) numlines++; result = (char **) pg_malloc(numlines * sizeof(char *)); toklen = strlen(token); replen = strlen(replacement); diff = replen - toklen; for (i = 0; i < numlines; i++) { char *where; char *newline; int pre; /* just copy pointer if NULL or no change needed */ if (lines[i] == NULL || (where = strstr(lines[i], token)) == NULL) { result[i] = lines[i]; continue; } /* if we get here a change is needed - set up new line */ newline = (char *) pg_malloc(strlen(lines[i]) + diff + 1); pre = where - lines[i]; strncpy(newline, lines[i], pre); strcpy(newline + pre, replacement); strcpy(newline + pre + replen, lines[i] + pre + toklen); result[i] = newline; } return result; }
综合上述两段，加入调试信息后，可以看到：
---------------replace for NAMEDATALEN ------start ===============lines[2301] OLD is : insert OID = 19 ( name 11 10 NAMEDATALEN f b S f t \054 0 18 1003 namein nameout namerecv namesend - - - c p f 0 -1 0 0 _null_ _null_ ) ===============result[2301] NEW is : insert OID = 19 ( name 11 10 64 f b S f t \054 0 18 1003 namein nameout namerecv namesend - - - c p f 0 -1 0 0 _null_ _null_ ) ===============lines[2458] OLD is : insert ( 1255 proname 19 -1 NAMEDATALEN 1 0 -1 -1 f p c t f f t 0 0 _null_ _null_) ===============result[2458] NEW is : insert ( 1255 proname 19 -1 64 1 0 -1 -1 f p c t f f t 0 0 _null_ _null_) ===============lines[2490] OLD is : insert ( 1247 typname 19 -1 NAMEDATALEN 1 0 -1 -1 f p c t f f t 0 0 _null_ _null_) ===============result[2490] NEW is : insert ( 1247 typname 19 -1 64 1 0 -1 -1 f p c t f f t 0 0 _null_ _null_) ===============lines[2527] OLD is : insert ( 1249 attname 19 -1 NAMEDATALEN 2 0 -1 -1 f p c t f f t 0 0 _null_ _null_) ===============result[2527] NEW is : insert ( 1249 attname 19 -1 64 2 0 -1 -1 f p c t f f t 0 0 _null_ _null_) ===============lines[2552] OLD is : insert ( 1259 relname 19 -1 NAMEDATALEN 1 0 -1 -1 f p c t f f t 0 0 _null_ _null_) ===============result[2552] NEW is : insert ( 1259 relname 19 -1 64 1 0 -1 -1 f p c t f f t 0 0 _null_ _null_) ---------------replace for NAMEDATALEN ------end ---------------replace for SIZEOF_POINTER ------start ===============lines[2428] OLD is : insert OID = 2281 ( internal 11 10 SIZEOF_POINTER t p P f t \054 0 0 0 internal_in internal_out - - - - - ALIGNOF_POINTER p f 0 -1 0 0 _null_ _null_ ) ===============result[2428] NEW is : insert OID = 2281 ( internal 11 10 8 t p P f t \054 0 0 0 internal_in internal_out - - - - - ALIGNOF_POINTER p f 0 -1 0 0 _null_ _null_ ) ---------------replace for SIZEOF_POINTER ------end ---------------replace for ALIGNOF_POINTER ------start ===============lines[2428] OLD is : insert OID = 2281 ( internal 11 10 8 t p P f t \054 0 0 0 internal_in internal_out - - - - - ALIGNOF_POINTER p f 0 -1 0 0 _null_ _null_ ) ===============result[2428] NEW is : insert OID = 2281 ( internal 11 10 8 t p P f t \054 0 0 0 internal_in internal_out - - - - - d p f 0 -1 0 0 _null_ _null_ ) ---------------replace for ALIGNOF_POINTER ------end ---------------replace for FLOAT4PASSBYVAL ------start ===============lines[2328] OLD is : insert OID = 700 ( float4 11 10 4 FLOAT4PASSBYVAL b N f t \054 0 0 1021 float4in float4out float4recv float4send - - - i p f 0 -1 0 0 _null_ _null_ ) ===============result[2328] NEW is : insert OID = 700 ( float4 11 10 4 true b N f t \054 0 0 1021 float4in float4out float4recv float4send - - - i p f 0 -1 0 0 _null_ _null_ ) ===============lines[2462] OLD is : insert ( 1255 procost 700 -1 4 5 0 -1 -1 FLOAT4PASSBYVAL p i t f f t 0 0 _null_ _null_) ===============result[2462] NEW is : insert ( 1255 procost 700 -1 4 5 0 -1 -1 true p i t f f t 0 0 _null_ _null_) ===============lines[2463] OLD is : insert ( 1255 prorows 700 -1 4 6 0 -1 -1 FLOAT4PASSBYVAL p i t f f t 0 0 _null_ _null_) ===============result[2463] NEW is : insert ( 1255 prorows 700 -1 4 6 0 -1 -1 true p i t f f t 0 0 _null_ _null_) ===============lines[2561] OLD is : insert ( 1259 reltuples 700 -1 4 10 0 -1 -1 FLOAT4PASSBYVAL p i t f f t 0 0 _null_ _null_) ===============result[2561] NEW is : insert ( 1259 reltuples 700 -1 4 10 0 -1 -1 true p i t f f t 0 0 _null_ _null_) ---------------replace for FLOAT4PASSBYVAL ------end ---------------replace for FLOAT8PASSBYVAL ------start ===============lines[2302] OLD is : insert OID = 20 ( int8 11 10 8 FLOAT8PASSBYVAL b N f t \054 0 0 1016 int8in int8out int8recv int8send - - - d p f 0 -1 0 0 _null_ _null_ ) ===============result[2302] NEW is : insert OID = 20 ( int8 11 10 8 true b N f t \054 0 0 1016 int8in int8out int8recv int8send - - - d p f 0 -1 0 0 _null_ _null_ ) ===============lines[2329] OLD is : insert OID = 701 ( float8 11 10 8 FLOAT8PASSBYVAL b N t t \054 0 0 1022 float8in float8out float8recv float8send - - - d p f 0 -1 0 0 _null_ _null_ ) ===============result[2329] NEW is : insert OID = 701 ( float8 11 10 8 true b N t t \054 0 0 1022 float8in float8out float8recv float8send - - - d p f 0 -1 0 0 _null_ _null_ ) ===============lines[2336] OLD is : insert OID = 790 ( money 11 10 8 FLOAT8PASSBYVAL b N f t \054 0 0 791 cash_in cash_out cash_recv cash_send - - - d p f 0 -1 0 0 _null_ _null_ ) ===============result[2336] NEW is : insert OID = 790 ( money 11 10 8 true b N f t \054 0 0 791 cash_in cash_out cash_recv cash_send - - - d p f 0 -1 0 0 _null_ _null_ ) ===============lines[2377] OLD is : insert OID = 1083 ( time 11 10 8 FLOAT8PASSBYVAL b D f t \054 0 0 1183 time_in time_out time_recv time_send timetypmodin timetypmodout - d p f 0 -1 0 0 _null_ _null_ ) ===============result[2377] NEW is : insert OID = 1083 ( time 11 10 8 true b D f t \054 0 0 1183 time_in time_out time_recv time_send timetypmodin timetypmodout - d p f 0 -1 0 0 _null_ _null_ ) ===============lines[2378] OLD is : insert OID = 1114 ( timestamp 11 10 8 FLOAT8PASSBYVAL b D f t \054 0 0 1115 timestamp_in timestamp_out timestamp_recv timestamp_send timestamptypmodin timestamptypmodout - d p f 0 -1 0 0 _null_ _null_ ) ===============result[2378] NEW is : insert OID = 1114 ( timestamp 11 10 8 true b D f t \054 0 0 1115 timestamp_in timestamp_out timestamp_recv timestamp_send timestamptypmodin timestamptypmodout - d p f 0 -1 0 0 _null_ _null_ ) ===============lines[2382] OLD is : insert OID = 1184 ( timestamptz 11 10 8 FLOAT8PASSBYVAL b D t t \054 0 0 1185 timestamptz_in timestamptz_out timestamptz_recv timestamptz_send timestamptztypmodin timestamptztypmodout - d p f 0 -1 0 0 _null_ _null_ ) ===============result[2382] NEW is : insert OID = 1184 ( timestamptz 11 10 8 true b D t t \054 0 0 1185 timestamptz_in timestamptz_out timestamptz_recv timestamptz_send timestamptztypmodin timestamptztypmodout - d p f 0 -1 0 0 _null_ _null_ ) ---------------replace for FLOAT4PASSBYVAL ------end ---------------replace for POSTGRES ------start ===============lines[4841] OLD is : insert OID = 10 ( "POSTGRES" t t t t t t t -1 _null_ _null_ ) ===============result[4841] NEW is : insert OID = 10 ( "pgsql" t t t t t t t -1 _null_ _null_ ) ---------------replace for POSTGRES ------end ---------------replace for ENCODING ------start ===============lines[4783] OLD is : insert OID = 1 ( template1 10 ENCODING "LC_COLLATE" "LC_CTYPE" t t -1 0 0 1663 _null_) ===============result[4783] NEW is : insert OID = 1 ( template1 10 6 "LC_COLLATE" "LC_CTYPE" t t -1 0 0 1663 _null_) ---------------replace for ENCODING ------end ---------------replace for LC_COLLATE ------start ===============lines[4783] OLD is : insert OID = 1 ( template1 10 6 "LC_COLLATE" "LC_CTYPE" t t -1 0 0 1663 _null_) ===============result[4783] NEW is : insert OID = 1 ( template1 10 6 "en_US.UTF-8" "LC_CTYPE" t t -1 0 0 1663 _null_) ---------------replace for LC_COLLATE ------end ---------------replace for LC_CTYPE ------start ===============lines[4783] OLD is : insert OID = 1 ( template1 10 6 "en_US.UTF-8" "LC_CTYPE" t t -1 0 0 1663 _null_) ===============result[4783] NEW is : insert OID = 1 ( template1 10 6 "en_US.UTF-8" "en_US.UTF-8" t t -1 0 0 1663 _null_) ---------------replace for LC_CTYPE ------end
这些被替换以后的信息，如何被使用呢？
看前面的 bootstrap_template1 函数中的这一段：
/* * Pass correct LC_xxx environment to bootstrap. * * The shell script arranged to restore the LC settings afterwards, but * there doesn't seem to be any compelling reason to do that. */ snprintf(cmd, sizeof(cmd), "LC_COLLATE=%s", lc_collate); putenv(xstrdup(cmd)); snprintf(cmd, sizeof(cmd), "LC_CTYPE=%s", lc_ctype); putenv(xstrdup(cmd)); unsetenv("LC_ALL"); /* Also ensure backend isn't confused by this environment var: */ unsetenv("PGCLIENTENCODING"); snprintf(cmd, sizeof(cmd), "\"%s\" --boot -x1 %s %s", backend_exec, boot_options, talkargs);
我可以得到 cmd是： "/home/pgsql/project/bin/postgres" --boot -x1 -F
而后面的一段：
则是一次一次的逐行带参数执行 Postgresql.bki中所有行（包括被替换的和没有被替换的行）
可以理解为特殊的模式下，向postgresql 的template 数据库中逐条写入数据。
PG_CMD_OPEN; for (line = bki_lines; *line != NULL; line++) { PG_CMD_PUTS(*line); free(*line); } PG_CMD_CLOSE;
需要注意的是，对各个系统表的建立，都是在此处，通过执行 postgres.bki文件中的各行脚本来完成的。
