X-Git-Url: https://ncurses.scripts.mit.edu/?p=ncurses.git;a=blobdiff_plain;f=ncurses%2Ftinfo%2Fdb_iterator.c;h=f0726682c40304151005374a458be949c48238fb;hp=fdc2bb09eadc0fd8f2eacaa628f8f95e245222c0;hb=81304798ee736c467839c779c9ca5dca48db7bea;hpb=7a27c7d49c2e8b4a1ecbe85b4423d647cbc75ea5 diff --git a/ncurses/tinfo/db_iterator.c b/ncurses/tinfo/db_iterator.c index fdc2bb09..f0726682 100644 --- a/ncurses/tinfo/db_iterator.c +++ b/ncurses/tinfo/db_iterator.c @@ -1,5 +1,6 @@ /**************************************************************************** - * Copyright (c) 2006,2007 Free Software Foundation, Inc. * + * Copyright 2018,2020 Thomas E. Dickey * + * Copyright 2006-2016,2017 Free Software Foundation, Inc. * * * * Permission is hereby granted, free of charge, to any person obtaining a * * copy of this software and associated documentation files (the * @@ -36,13 +37,170 @@ #include +#include #include -MODULE_ID("$Id: db_iterator.c,v 1.6 2007/04/22 00:00:26 tom Exp $") +#if USE_HASHED_DB +#include +#endif + +MODULE_ID("$Id: db_iterator.c,v 1.48 2020/02/02 23:34:34 tom Exp $") #define HaveTicDirectory _nc_globals.have_tic_directory #define KeepTicDirectory _nc_globals.keep_tic_directory #define TicDirectory _nc_globals.tic_directory +#define my_blob _nc_globals.dbd_blob +#define my_list _nc_globals.dbd_list +#define my_size _nc_globals.dbd_size +#define my_time _nc_globals.dbd_time +#define my_vars _nc_globals.dbd_vars + +static void +add_to_blob(const char *text, size_t limit) +{ + (void) limit; + + if (*text != '\0') { + char *last = my_blob + strlen(my_blob); + if (last != my_blob) + *last++ = NCURSES_PATHSEP; + _nc_STRCPY(last, text, limit); + } +} + +static bool +check_existence(const char *name, struct stat *sb) +{ + bool result = FALSE; + + if (quick_prefix(name)) { + result = TRUE; + } else if (stat(name, sb) == 0 + && (S_ISDIR(sb->st_mode) + || (S_ISREG(sb->st_mode) && sb->st_size))) { + result = TRUE; + } +#if USE_HASHED_DB + else if (strlen(name) < PATH_MAX - sizeof(DBM_SUFFIX)) { + char temp[PATH_MAX]; + _nc_SPRINTF(temp, _nc_SLIMIT(sizeof(temp)) "%s%s", name, DBM_SUFFIX); + if (stat(temp, sb) == 0 && S_ISREG(sb->st_mode) && sb->st_size) { + result = TRUE; + } + } +#endif + return result; +} + +/* + * Trim newlines (and backslashes preceding those) and tab characters to + * help simplify scripting of the quick-dump feature. Leave spaces and + * other backslashes alone. + */ +static void +trim_formatting(char *source) +{ + char *target = source; + char ch; + + while ((ch = *source++) != '\0') { + if (ch == '\\' && *source == '\n') + continue; + if (ch == '\n' || ch == '\t') + continue; + *target++ = ch; + } + *target = '\0'; +} + +/* + * Store the latest value of an environment variable in my_vars[] so we can + * detect if one changes, invalidating the cached search-list. + */ +static bool +update_getenv(const char *name, DBDIRS which) +{ + bool result = FALSE; + + if (which < dbdLAST) { + char *value; + char *cached_value = my_vars[which].value; + bool same_value; + + if ((value = getenv(name)) != 0) { + value = strdup(value); + } + same_value = ((value == 0 && cached_value == 0) || + (value != 0 && + cached_value != 0 && + strcmp(value, cached_value) == 0)); + + /* Set variable name to enable checks in cache_expired(). */ + my_vars[which].name = name; + + if (!same_value) { + FreeIfNeeded(my_vars[which].value); + my_vars[which].value = value; + result = TRUE; + } else { + free(value); + } + } + return result; +} + +#if NCURSES_USE_DATABASE || NCURSES_USE_TERMCAP +static char * +cache_getenv(const char *name, DBDIRS which) +{ + char *result = 0; + + (void) update_getenv(name, which); + if (which < dbdLAST) { + result = my_vars[which].value; + } + return result; +} +#endif + +/* + * The cache expires if at least a second has passed since the initial lookup, + * or if one of the environment variables changed. + * + * Only a few applications use multiple lookups of terminal entries, seems that + * aside from bulk I/O such as tic and toe, that leaves interactive programs + * which should not be modifying the terminal databases in a way that would + * invalidate the search-list. + * + * The "1-second" is to allow for user-directed changes outside the program. + */ +static bool +cache_expired(void) +{ + bool result = FALSE; + time_t now = time((time_t *) 0); + + if (now > my_time) { + result = TRUE; + } else { + DBDIRS n; + for (n = (DBDIRS) 0; n < dbdLAST; ++n) { + if (my_vars[n].name != 0 + && update_getenv(my_vars[n].name, n)) { + result = TRUE; + break; + } + } + } + return result; +} + +static void +free_cache(void) +{ + FreeAndNull(my_blob); + FreeAndNull(my_list); +} /* * Record the "official" location of the terminfo directory, according to @@ -51,17 +209,20 @@ MODULE_ID("$Id: db_iterator.c,v 1.6 2007/04/22 00:00:26 tom Exp $") NCURSES_EXPORT(const char *) _nc_tic_dir(const char *path) { + T(("_nc_tic_dir %s", NonNull(path))); if (!KeepTicDirectory) { if (path != 0) { TicDirectory = path; HaveTicDirectory = TRUE; - } else if (!HaveTicDirectory && use_terminfo_vars()) { - char *envp; - if ((envp = getenv("TERMINFO")) != 0) - return _nc_tic_dir(envp); + } else if (HaveTicDirectory == 0) { + if (use_terminfo_vars()) { + const char *envp; + if ((envp = getenv("TERMINFO")) != 0) + return _nc_tic_dir(envp); + } } } - return TicDirectory; + return TicDirectory ? TicDirectory : TERMINFO; } /* @@ -76,63 +237,17 @@ _nc_keep_tic_dir(const char *path) KeepTicDirectory = TRUE; } -/* - * Process the list of :-separated directories, looking for the terminal type. - * We don't use strtok because it does not show us empty tokens. - */ -#define ThisDbList _nc_globals.dbi_list -#define ThisDbSize _nc_globals.dbi_size - /* * Cleanup. */ NCURSES_EXPORT(void) _nc_last_db(void) { - if (ThisDbList != 0) { - FreeAndNull(ThisDbList); - } - ThisDbSize = 0; -} - -/* The TERMINFO_DIRS value, if defined by the configure script, begins with a - * ":", which will be interpreted as TERMINFO. - */ -static const char * -next_list_item(const char *source, int *offset) -{ - if (source != 0) { - FreeIfNeeded(ThisDbList); - ThisDbList = strdup(source); - ThisDbSize = strlen(source); - } - - if (ThisDbList != 0 && ThisDbSize && *offset < ThisDbSize) { - static char system_db[] = TERMINFO; - char *result = ThisDbList + *offset; - char *marker = strchr(result, NCURSES_PATHSEP); - - /* - * Put a null on the marker if a separator was found. Set the offset - * to the next position after the marker so we can call this function - * again, using the data at the offset. - */ - if (marker == 0) { - *offset += strlen(result) + 1; - marker = result + *offset; - } else { - *marker++ = 0; - *offset = marker - ThisDbList; - } - if (*result == 0 && result != (ThisDbList + ThisDbSize)) - result = system_db; - return result; + if (my_blob != 0 && cache_expired()) { + free_cache(); } - return 0; } -#define NEXT_DBD(var, offset) next_list_item((*offset == 0) ? var : 0, offset) - /* * This is a simple iterator which allows the caller to step through the * possible locations for a terminfo directory. ncurses uses this to find @@ -142,84 +257,192 @@ NCURSES_EXPORT(const char *) _nc_next_db(DBDIRS * state, int *offset) { const char *result; - char *envp; - - while (*state < dbdLAST) { - DBDIRS next = (DBDIRS) ((int) (*state) + 1); + (void) offset; + if ((int) *state < my_size + && my_list != 0 + && my_list[*state] != 0) { + result = my_list[*state]; + (*state)++; + } else { result = 0; + } + if (result != 0) { + T(("_nc_next_db %d %s", *state, result)); + } + return result; +} - switch (*state) { - case dbdTIC: - if (HaveTicDirectory) - result = _nc_tic_dir(0); - break; -#if USE_DATABASE - case dbdEnvOnce: - if (use_terminfo_vars()) { - if ((envp = getenv("TERMINFO")) != 0) - result = _nc_tic_dir(envp); - } - break; - case dbdHome: - if (use_terminfo_vars()) { - result = _nc_home_terminfo(); - } - break; - case dbdEnvList: - if (use_terminfo_vars()) { - if ((result = NEXT_DBD(getenv("TERMINFO_DIRS"), offset)) != 0) - next = *state; - } - break; - case dbdCfgList: +NCURSES_EXPORT(void) +_nc_first_db(DBDIRS * state, int *offset) +{ + bool cache_has_expired = FALSE; + *state = dbdTIC; + *offset = 0; + + T((T_CALLED("_nc_first_db"))); + + /* build a blob containing all of the strings we will use for a lookup + * table. + */ + if (my_blob == 0 || (cache_has_expired = cache_expired())) { + size_t blobsize = 0; + const char *values[dbdLAST]; + struct stat *my_stat; + int j; + + if (cache_has_expired) + free_cache(); + + for (j = 0; j < dbdLAST; ++j) + values[j] = 0; + + /* + * This is the first item in the list, and is used only when tic is + * writing to the database, as a performance improvement. + */ + values[dbdTIC] = TicDirectory; + +#if NCURSES_USE_DATABASE #ifdef TERMINFO_DIRS - if ((result = NEXT_DBD(TERMINFO_DIRS, offset)) != 0) - next = *state; + values[dbdCfgList] = TERMINFO_DIRS; #endif - break; - case dbdCfgOnce: -#ifndef TERMINFO_DIRS - result = TERMINFO; +#ifdef TERMINFO + values[dbdCfgOnce] = TERMINFO; #endif - break; -#endif /* USE_DATABASE */ -#if USE_TERMCAP - case dbdEnvOnce2: - if (use_terminfo_vars()) { - if ((envp = getenv("TERMCAP")) != 0) - result = _nc_tic_dir(envp); - } - break; - case dbdEnvList2: - if (use_terminfo_vars()) { - if ((result = NEXT_DBD(getenv("TERMPATH"), offset)) != 0) - next = *state; +#endif + +#if NCURSES_USE_TERMCAP + values[dbdCfgList2] = TERMPATH; +#endif + + if (use_terminfo_vars()) { +#if NCURSES_USE_DATABASE + values[dbdEnvOnce] = cache_getenv("TERMINFO", dbdEnvOnce); + values[dbdHome] = _nc_home_terminfo(); + (void) cache_getenv("HOME", dbdHome); + values[dbdEnvList] = cache_getenv("TERMINFO_DIRS", dbdEnvList); + +#endif +#if NCURSES_USE_TERMCAP + values[dbdEnvOnce2] = cache_getenv("TERMCAP", dbdEnvOnce2); + /* only use $TERMCAP if it is an absolute path */ + if (values[dbdEnvOnce2] != 0 + && *values[dbdEnvOnce2] != '/') { + values[dbdEnvOnce2] = 0; } - break; - case dbdCfgList2: - if ((result = NEXT_DBD(TERMPATH, offset)) != 0) - next = *state; - break; -#endif /* USE_TERMCAP */ - case dbdLAST: - break; + values[dbdEnvList2] = cache_getenv("TERMPATH", dbdEnvList2); +#endif /* NCURSES_USE_TERMCAP */ } - if (*state != next) { - *state = next; - *offset = 0; - _nc_last_db(); + + for (j = 0; j < dbdLAST; ++j) { + if (values[j] == 0) + values[j] = ""; + blobsize += 2 + strlen(values[j]); } - if (result != 0) { - return result; + + my_blob = malloc(blobsize); + if (my_blob != 0) { + *my_blob = '\0'; + for (j = 0; j < dbdLAST; ++j) { + add_to_blob(values[j], blobsize); + } + + /* Now, build an array which will be pointers to the distinct + * strings in the blob. + */ + blobsize = 2; + for (j = 0; my_blob[j] != '\0'; ++j) { + if (my_blob[j] == NCURSES_PATHSEP) + ++blobsize; + } + my_list = typeCalloc(char *, blobsize); + my_stat = typeCalloc(struct stat, blobsize); + if (my_list != 0 && my_stat != 0) { + int k = 0; + my_list[k++] = my_blob; + for (j = 0; my_blob[j] != '\0'; ++j) { + if (my_blob[j] == NCURSES_PATHSEP + && ((&my_blob[j] - my_list[k - 1]) != 3 + || !quick_prefix(my_list[k - 1]))) { + my_blob[j] = '\0'; + my_list[k++] = &my_blob[j + 1]; + } + } + + /* + * Eliminate duplicates from the list. + */ + for (j = 0; my_list[j] != 0; ++j) { +#ifdef TERMINFO + if (*my_list[j] == '\0') + my_list[j] = strdup(TERMINFO); +#endif + trim_formatting(my_list[j]); + for (k = 0; k < j; ++k) { + if (!strcmp(my_list[j], my_list[k])) { + T(("duplicate %s", my_list[j])); + k = j - 1; + while ((my_list[j] = my_list[j + 1]) != 0) { + ++j; + } + j = k; + break; + } + } + } + + /* + * Eliminate non-existent databases, and those that happen to + * be symlinked to another location. + */ + for (j = 0; my_list[j] != 0; ++j) { + bool found = check_existence(my_list[j], &my_stat[j]); +#if HAVE_LINK + if (found) { + for (k = 0; k < j; ++k) { + if (my_stat[j].st_dev == my_stat[k].st_dev + && my_stat[j].st_ino == my_stat[k].st_ino) { + found = FALSE; + break; + } + } + } +#endif + if (!found) { + T(("not found %s", my_list[j])); + k = j; + while ((my_list[k] = my_list[k + 1]) != 0) { + ++k; + } + --j; + } + } + my_size = j; + my_time = time((time_t *) 0); + } else { + FreeAndNull(my_blob); + } + free(my_stat); } } - return 0; + returnVoid; } -NCURSES_EXPORT(void) -_nc_first_db(DBDIRS * state, int *offset) +#if NO_LEAKS +void +_nc_db_iterator_leaks(void) { - *state = dbdTIC; - *offset = 0; + DBDIRS which; + + if (my_blob != 0) + FreeAndNull(my_blob); + if (my_list != 0) + FreeAndNull(my_list); + for (which = 0; (int) which < dbdLAST; ++which) { + my_vars[which].name = 0; + FreeIfNeeded(my_vars[which].value); + my_vars[which].value = 0; + } } +#endif