mongo/test/format/config.c

/*-
 * Public Domain 2014-2016 MongoDB, Inc.
 * Public Domain 2008-2014 WiredTiger, Inc.
 *
 * This is free and unencumbered software released into the public domain.
 *
 * Anyone is free to copy, modify, publish, use, compile, sell, or
 * distribute this software, either in source code form or as a compiled
 * binary, for any purpose, commercial or non-commercial, and by any
 * means.
 *
 * In jurisdictions that recognize copyright laws, the author or authors
 * of this software dedicate any and all copyright interest in the
 * software to the public domain. We make this dedication for the benefit
 * of the public at large and to the detriment of our heirs and
 * successors. We intend this dedication to be an overt act of
 * relinquishment in perpetuity of all present and future rights to this
 * software under copyright law.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

#include "format.h"
#include "config.h"

static void	   config_checksum(void);
static void	   config_compression(const char *);
static void	   config_encryption(void);
static const char *config_file_type(u_int);
static CONFIG	  *config_find(const char *, size_t);
static void	   config_in_memory(void);
static void	   config_in_memory_check(void);
static int	   config_is_perm(const char *);
static void	   config_isolation(void);
static void	   config_lrt(void);
static void	   config_map_checksum(const char *, u_int *);
static void	   config_map_compression(const char *, u_int *);
static void	   config_map_encryption(const char *, u_int *);
static void	   config_map_file_type(const char *, u_int *);
static void	   config_map_isolation(const char *, u_int *);
static void	   config_reset(void);

/*
 * config_setup --
 *	Initialize configuration for a run.
 */
void
config_setup(void)
{
	CONFIG *cp;

	/* Clear any temporary values. */
	config_reset();

	/* Periodically run in-memory. */
	config_in_memory();

	/*
	 * Choose a data source type and a file type: they're interrelated (LSM
	 * trees are only compatible with row-store) and other items depend on
	 * them.
	 */
	if (!config_is_perm("data_source"))
		switch (mmrand(NULL, 1, 3)) {
		case 1:
			config_single("data_source=file", 0);
			break;
		case 2:
			if (!g.c_in_memory) {
				config_single("data_source=lsm", 0);
				break;
			}
			/* FALLTHROUGH */
		case 3:
			config_single("data_source=table", 0);
			break;
		}

	if (!config_is_perm("file_type"))
		switch (DATASOURCE("lsm") ? 5 : mmrand(NULL, 1, 10)) {
		case 1:
			config_single("file_type=fix", 0);
			break;
		case 2: case 3: case 4:
			config_single("file_type=var", 0);
			break;
		case 5: case 6: case 7: case 8: case 9: case 10:
			config_single("file_type=row", 0);
			break;
		}
	config_map_file_type(g.c_file_type, &g.type);

	/*
	 * If data_source and file_type were both "permanent", we may still
	 * have a mismatch.
	 */
	if (DATASOURCE("lsm") && g.type != ROW) {
		fprintf(stderr,
	    "%s: lsm data_source is only compatible with row file_type\n",
		    g.progname);
		exit(EXIT_FAILURE);
	}

	/*
	 * Build the top-level object name: we're overloading data_source in
	 * our configuration, LSM or KVS devices are "tables", but files are
	 * tested as well.
	 */
	g.uri = dmalloc(256);
	strcpy(g.uri, DATASOURCE("file") ? "file:" : "table:");
	if (DATASOURCE("helium"))
		strcat(g.uri, "dev1/");
	strcat(g.uri, WT_NAME);

	/* Fill in random values for the rest of the run. */
	for (cp = c; cp->name != NULL; ++cp) {
		if (F_ISSET(cp, C_IGNORE | C_PERM | C_TEMP))
			continue;

		/*
		 * Boolean flags are 0 or 1, but only set N in 100 where the
		 * variable's min value is N.  Set the flag if we rolled >=
		 * the min, 0 otherwise.
		 */
		if (F_ISSET(cp, C_BOOL))
			*cp->v = mmrand(NULL, 1, 100) <= cp->min ? 1 : 0;
		else
			*cp->v = mmrand(NULL, cp->min, cp->maxrand);
	}

	/* Required shared libraries. */
	if (DATASOURCE("helium") && access(HELIUM_PATH, R_OK) != 0)
		testutil_die(errno,
		    "Levyx/helium shared library: %s", HELIUM_PATH);
	if (DATASOURCE("kvsbdb") && access(KVS_BDB_PATH, R_OK) != 0)
		testutil_die(errno, "kvsbdb shared library: %s", KVS_BDB_PATH);

	/* Some data-sources don't support user-specified collations. */
	if (DATASOURCE("helium") || DATASOURCE("kvsbdb"))
		config_single("reverse=off", 0);

	/*
	 * Periodically, run single-threaded so we can compare the results to
	 * a Berkeley DB copy, as long as the thread-count isn't nailed down.
	 * Don't do it on the first run, all our smoke tests would hit it.
	 */
	if (!g.replay && g.run_cnt % 20 == 19 && !config_is_perm("threads"))
		g.c_threads = 1;

	config_checksum();
	config_compression("compression");
	config_compression("logging_compression");
	config_encryption();
	config_isolation();
	config_lrt();

	/*
	 * Periodically, set the delete percentage to 0 so salvage gets run,
	 * as long as the delete percentage isn't nailed down.
	 * Don't do it on the first run, all our smoke tests would hit it.
	 */
	if (!g.replay && g.run_cnt % 10 == 9 && !config_is_perm("delete_pct"))
		config_single("delete_pct=0", 0);

	/*
	 * If this is an LSM run, set the cache size and crank up the insert
	 * percentage.
	 */
	if (DATASOURCE("lsm")) {
		if (!config_is_perm("cache"))
			g.c_cache = 30 * g.c_chunk_size;

		if (!config_is_perm("insert_pct"))
			g.c_insert_pct = mmrand(NULL, 50, 85);
	}

	/* Ensure there is at least 1MB of cache per thread. */
	if (!config_is_perm("cache") && g.c_cache < g.c_threads)
		g.c_cache = g.c_threads;

	/* Give in-memory configuration a final review. */
	config_in_memory_check();

	/* Make the default maximum-run length 20 minutes. */
	if (!config_is_perm("timer"))
		config_single("timer=20", 0);

	/*
	 * Key/value minimum/maximum are related, correct unless specified by
	 * the configuration.
	 */
	if (!config_is_perm("key_min") && g.c_key_min > g.c_key_max)
		g.c_key_min = g.c_key_max;
	if (!config_is_perm("key_max") && g.c_key_max < g.c_key_min)
		g.c_key_max = g.c_key_min;
	if (g.c_key_min > g.c_key_max)
		testutil_die(EINVAL, "key_min may not be larger than key_max");

	if (!config_is_perm("value_min") && g.c_value_min > g.c_value_max)
		g.c_value_min = g.c_value_max;
	if (!config_is_perm("value_max") && g.c_value_max < g.c_value_min)
		g.c_value_max = g.c_value_min;
	if (g.c_value_min > g.c_value_max)
		testutil_die(EINVAL,
		    "value_min may not be larger than value_max");

	/* Reset the key count. */
	g.key_cnt = 0;
}

/*
 * config_checksum --
 *	Checksum configuration.
 */
static void
config_checksum(void)
{
	/* Choose a checksum mode if nothing was specified. */
	if (!config_is_perm("checksum"))
		switch (mmrand(NULL, 1, 10)) {
		case 1:					/* 10% */
			config_single("checksum=on", 0);
			break;
		case 2:					/* 10% */
			config_single("checksum=off", 0);
			break;
		default:				/* 80% */
			config_single("checksum=uncompressed", 0);
			break;
		}
}

/*
 * config_compression --
 *	Compression configuration.
 */
static void
config_compression(const char *conf_name)
{
	const char *cstr;
	char confbuf[128];

	/* Return if already specified. */
	if (config_is_perm(conf_name))
		return;

	/*
	 * Don't configure a compression engine for logging if logging isn't
	 * configured (it won't break, but it's confusing).
	 */
	cstr = "none";
	if (strcmp(conf_name, "logging_compression") == 0 && g.c_logging == 0) {
		(void)snprintf(
		    confbuf, sizeof(confbuf), "%s=%s", conf_name, cstr);
		config_single(confbuf, 0);
		return;
	}

	/*
	 * Select a compression type from the list of built-in engines.
	 *
	 * Listed percentages are only correct if all of the possible engines
	 * are compiled in.
	 */
	switch (mmrand(NULL, 1, 20)) {
#ifdef HAVE_BUILTIN_EXTENSION_LZ4
	case 1: case 2: case 3: case 4:		/* 20% lz4 */
		cstr = "lz4";
		break;
	case 5:					/* 5% lz4-no-raw */
		cstr = "lz4-noraw";
		break;
#endif
#ifdef HAVE_BUILTIN_EXTENSION_SNAPPY
	case 6: case 7: case 8: case 9:		/* 30% snappy */
	case 10: case 11:
		cstr = "snappy";
		break;
#endif
#ifdef HAVE_BUILTIN_EXTENSION_ZLIB
	case 12: case 13: case 14: case 15:	/* 20% zlib */
		cstr = "zlib";
		break;
	case 16:				/* 5% zlib-no-raw */
		cstr = "zlib-noraw";
		break;
#endif
	case 17: case 18: case 19: case 20:	/* 20% no compression */
	default:
		break;
	}

	(void)snprintf(confbuf, sizeof(confbuf), "%s=%s", conf_name, cstr);
	config_single(confbuf, 0);
}

/*
 * config_encryption --
 *	Encryption configuration.
 */
static void
config_encryption(void)
{
	const char *cstr;

	/*
	 * Encryption: choose something if encryption wasn't specified.
	 */
	if (!config_is_perm("encryption")) {
		cstr = "encryption=none";
		switch (mmrand(NULL, 1, 10)) {
		case 1: case 2: case 3: case 4: case 5:	/* 70% no encryption */
		case 6: case 7:
			break;
		case 8: case 9: case 10:		/* 30% rotn */
			cstr = "encryption=rotn-7";
			break;
		}

		config_single(cstr, 0);
	}
}

/*
 * config_in_memory --
 *	Periodically set up an in-memory configuration.
 */
static void
config_in_memory(void)
{
	/*
	 * Configure in-memory before configuring anything else, in-memory has
	 * many related requirements. Don't configure in-memory if there's any
	 * incompatible configurations, so we don't have to configure in-memory
	 * every time we configure something like LSM, that's too painful.
	 */
	if (config_is_perm("backups"))
		return;
	if (config_is_perm("checkpoints"))
		return;
	if (config_is_perm("compression"))
		return;
	if (config_is_perm("data_source") && DATASOURCE("lsm"))
		return;
	if (config_is_perm("logging"))
		return;
	if (config_is_perm("rebalance"))
		return;
	if (config_is_perm("salvage"))
		return;
	if (config_is_perm("verify"))
		return;

	if (!config_is_perm("in_memory") && mmrand(NULL, 1, 20) == 1)
		g.c_in_memory = 1;
}

/*
 * config_in_memory_check --
 *	In-memory configuration review.
 */
static void
config_in_memory_check(void)
{
	uint32_t cache;

	if (g.c_in_memory == 0)
		return;

	/* Turn off a lot of stuff. */
	if (!config_is_perm("backups"))
		config_single("backups=off", 0);
	if (!config_is_perm("checkpoints"))
		config_single("checkpoints=off", 0);
	if (!config_is_perm("compression"))
		config_single("compression=none", 0);
	if (!config_is_perm("logging"))
		config_single("logging=off", 0);
	if (!config_is_perm("rebalance"))
		config_single("rebalance=off", 0);
	if (!config_is_perm("salvage"))
		config_single("salvage=off", 0);
	if (!config_is_perm("verify"))
		config_single("verify=off", 0);

	/*
	 * Keep keys/values small, overflow items aren't an issue for in-memory
	 * configurations and it keeps us from overflowing the cache.
	 */
	if (!config_is_perm("key_max"))
		config_single("key_max=32", 0);
	if (!config_is_perm("value_max"))
		config_single("value_max=80", 0);

	/*
	 * Size the cache relative to the initial data set, use 2x the base
	 * size as a minimum.
	 */
	if (!config_is_perm("cache")) {
		cache = g.c_value_max;
		if (g.type == ROW)
			cache += g.c_key_max;
		cache *= g.c_rows;
		cache *= 2;
		cache /= WT_MEGABYTE;
		if (g.c_cache < cache)
			g.c_cache = cache;
	}
}

/*
 * config_isolation --
 *	Isolation configuration.
 */
static void
config_isolation(void)
{
	const char *cstr;

	/*
	 * Isolation: choose something if isolation wasn't specified.
	 */
	if (!config_is_perm("isolation")) {
		/* Avoid "maybe uninitialized" warnings. */
		switch (mmrand(NULL, 1, 4)) {
		case 1:
			cstr = "isolation=random";
			break;
		case 2:
			cstr = "isolation=read-uncommitted";
			break;
		case 3:
			cstr = "isolation=read-committed";
			break;
		case 4:
		default:
			cstr = "isolation=snapshot";
			break;
		}
		config_single(cstr, 0);
	}
}

/*
 * config_lrt --
 *	Long-running transaction configuration.
 */
static void
config_lrt(void)
{
	/*
	 * WiredTiger doesn't support a lookaside file for fixed-length column
	 * stores.
	 */
	if (g.type == FIX) {
		if (config_is_perm("long_running_txn"))
			testutil_die(EINVAL,
			    "long_running_txn not supported with fixed-length "
			    "column store");
		config_single("long_running_txn=off", 0);
	}
}

/*
 * config_error --
 *	Display configuration information on error.
 */
void
config_error(void)
{
	CONFIG *cp;

	/* Display configuration names. */
	fprintf(stderr, "\n");
	fprintf(stderr, "Configuration names:\n");
	for (cp = c; cp->name != NULL; ++cp)
		if (strlen(cp->name) > 17)
			fprintf(stderr,
			    "%s\n%17s: %s\n", cp->name, " ", cp->desc);
		else
			fprintf(stderr, "%17s: %s\n", cp->name, cp->desc);
}

/*
 * config_print --
 *	Print configuration information.
 */
void
config_print(int error_display)
{
	CONFIG *cp;
	FILE *fp;

	if (error_display)
		fp = stdout;
	else
		if ((fp = fopen(g.home_config, "w")) == NULL)
			testutil_die(errno, "fopen: %s", g.home_config);

	fprintf(fp, "############################################\n");
	fprintf(fp, "#  RUN PARAMETERS\n");
	fprintf(fp, "############################################\n");

	/* Display configuration values. */
	for (cp = c; cp->name != NULL; ++cp)
		if (F_ISSET(cp, C_STRING))
			fprintf(fp, "%s=%s\n", cp->name,
			    *cp->vstr == NULL ? "" : *cp->vstr);
		else
			fprintf(fp, "%s=%" PRIu32 "\n", cp->name, *cp->v);

	fprintf(fp, "############################################\n");

	/* Flush so we're up-to-date on error. */
	(void)fflush(fp);

	if (fp != stdout)
		fclose_and_clear(&fp);
}

/*
 * config_file --
 *	Read configuration values from a file.
 */
void
config_file(const char *name)
{
	FILE *fp;
	char *p, buf[256];

	if ((fp = fopen(name, "r")) == NULL)
		testutil_die(errno, "fopen: %s", name);
	while (fgets(buf, sizeof(buf), fp) != NULL) {
		for (p = buf; *p != '\0' && *p != '\n'; ++p)
			;
		*p = '\0';
		if (buf[0] == '\0' || buf[0] == '#')
			continue;
		config_single(buf, 1);
	}
	fclose_and_clear(&fp);
}

/*
 * config_clear --
 *	Clear all configuration values.
 */
void
config_clear(void)
{
	CONFIG *cp;

	/* Clear all allocated configuration data. */
	for (cp = c; cp->name != NULL; ++cp)
		if (cp->vstr != NULL) {
			free((void *)*cp->vstr);
			*cp->vstr = NULL;
		}
	free(g.uri);
	g.uri = NULL;
}

/*
 * config_reset --
 *	Clear per-run configuration values.
 */
static void
config_reset(void)
{
	CONFIG *cp;

	/* Clear temporary allocated configuration data. */
	for (cp = c; cp->name != NULL; ++cp) {
		F_CLR(cp, C_TEMP);
		if (!F_ISSET(cp, C_PERM) && cp->vstr != NULL) {
			free((void *)*cp->vstr);
			*cp->vstr = NULL;
		}
	}
	free(g.uri);
	g.uri = NULL;
}

/*
 * config_single --
 *	Set a single configuration structure value.
 */
void
config_single(const char *s, int perm)
{
	CONFIG *cp;
	long v;
	char *p;
	const char *ep;

	if ((ep = strchr(s, '=')) == NULL) {
		fprintf(stderr,
		    "%s: %s: illegal configuration value\n", g.progname, s);
		exit(EXIT_FAILURE);
	}

	cp = config_find(s, (size_t)(ep - s));
	F_SET(cp, perm ? C_PERM : C_TEMP);
	++ep;

	if (F_ISSET(cp, C_STRING)) {
		if (strncmp(s, "data_source", strlen("data_source")) == 0 &&
		    strncmp("file", ep, strlen("file")) != 0 &&
		    strncmp("helium", ep, strlen("helium")) != 0 &&
		    strncmp("kvsbdb", ep, strlen("kvsbdb")) != 0 &&
		    strncmp("lsm", ep, strlen("lsm")) != 0 &&
		    strncmp("table", ep, strlen("table")) != 0) {
			    fprintf(stderr,
				"Invalid data source option: %s\n", ep);
			    exit(EXIT_FAILURE);
		}

		/*
		 * Free the previous setting if a configuration has been
		 * passed in twice.
		 */
		if (*cp->vstr != NULL) {
			free(*cp->vstr);
			*cp->vstr = NULL;
		}

		if (strncmp(s, "checksum", strlen("checksum")) == 0) {
			config_map_checksum(ep, &g.c_checksum_flag);
			*cp->vstr = dstrdup(ep);
		} else if (strncmp(
		    s, "compression", strlen("compression")) == 0) {
			config_map_compression(ep, &g.c_compression_flag);
			*cp->vstr = dstrdup(ep);
		} else if (strncmp(
		    s, "encryption", strlen("encryption")) == 0) {
			config_map_encryption(ep, &g.c_encryption_flag);
			*cp->vstr = dstrdup(ep);
		} else if (strncmp(s, "isolation", strlen("isolation")) == 0) {
			config_map_isolation(ep, &g.c_isolation_flag);
			*cp->vstr = dstrdup(ep);
		} else if (strncmp(s, "file_type", strlen("file_type")) == 0) {
			config_map_file_type(ep, &g.type);
			*cp->vstr = dstrdup(config_file_type(g.type));
		} else if (strncmp(s, "logging_compression",
		    strlen("logging_compression")) == 0) {
			config_map_compression(ep,
			    &g.c_logging_compression_flag);
			*cp->vstr = dstrdup(ep);
		} else {
			free((void *)*cp->vstr);
			*cp->vstr = dstrdup(ep);
		}

		return;
	}

	v = -1;
	if (F_ISSET(cp, C_BOOL)) {
		if (strncmp(ep, "off", strlen("off")) == 0)
			v = 0;
		else if (strncmp(ep, "on", strlen("on")) == 0)
			v = 1;
	}
	if (v == -1) {
		v = strtol(ep, &p, 10);
		if (*p != '\0') {
			fprintf(stderr, "%s: %s: illegal numeric value\n",
			    g.progname, s);
			exit(EXIT_FAILURE);
		}
	}
	if (F_ISSET(cp, C_BOOL)) {
		if (v != 0 && v != 1) {
			fprintf(stderr, "%s: %s: value of boolean not 0 or 1\n",
			    g.progname, s);
			exit(EXIT_FAILURE);
		}
	} else if (v < cp->min || v > cp->maxset) {
		fprintf(stderr, "%s: %s: value outside min/max values of %"
		    PRIu32 "-%" PRIu32 "\n",
		    g.progname, s, cp->min, cp->maxset);
		exit(EXIT_FAILURE);
	}
	*cp->v = (uint32_t)v;
}

/*
 * config_map_file_type --
 *	Map a file type configuration to a flag.
 */
static void
config_map_file_type(const char *s, u_int *vp)
{
	if (strcmp(s, "fix") == 0 ||
	    strcmp(s, "fixed-length column-store") == 0)
		*vp = FIX;
	else if (strcmp(s, "var") == 0 ||
	    strcmp(s, "variable-length column-store") == 0)
		*vp = VAR;
	else if (strcmp(s, "row") == 0 ||
	    strcmp(s, "row-store") == 0)
		*vp = ROW;
	else
		testutil_die(EINVAL, "illegal file type configuration: %s", s);
}

/*
 * config_map_checksum --
 *	Map a checksum configuration to a flag.
 */
static void
config_map_checksum(const char *s, u_int *vp)
{
	if (strcmp(s, "on") == 0)
		*vp = CHECKSUM_ON;
	else if (strcmp(s, "off") == 0)
		*vp = CHECKSUM_ON;
	else if (strcmp(s, "uncompressed") == 0)
		*vp = CHECKSUM_UNCOMPRESSED;
	else
		testutil_die(EINVAL, "illegal checksum configuration: %s", s);
}

/*
 * config_map_compression --
 *	Map a compression configuration to a flag.
 */
static void
config_map_compression(const char *s, u_int *vp)
{
	if (strcmp(s, "none") == 0)
		*vp = COMPRESS_NONE;
	else if (strcmp(s, "lz4") == 0)
		*vp = COMPRESS_LZ4;
	else if (strcmp(s, "lz4-noraw") == 0)
		*vp = COMPRESS_LZ4_NO_RAW;
	else if (strcmp(s, "lzo") == 0)
		*vp = COMPRESS_LZO;
	else if (strcmp(s, "snappy") == 0)
		*vp = COMPRESS_SNAPPY;
	else if (strcmp(s, "zlib") == 0)
		*vp = COMPRESS_ZLIB;
	else if (strcmp(s, "zlib-noraw") == 0)
		*vp = COMPRESS_ZLIB_NO_RAW;
	else
		testutil_die(EINVAL,
		    "illegal compression configuration: %s", s);
}

/*
 * config_map_encryption --
 *	Map a encryption configuration to a flag.
 */
static void
config_map_encryption(const char *s, u_int *vp)
{
	if (strcmp(s, "none") == 0)
		*vp = ENCRYPT_NONE;
	else if (strcmp(s, "rotn-7") == 0)
		*vp = ENCRYPT_ROTN_7;
	else
		testutil_die(EINVAL, "illegal encryption configuration: %s", s);
}

/*
 * config_map_isolation --
 *	Map an isolation configuration to a flag.
 */
static void
config_map_isolation(const char *s, u_int *vp)
{
	if (strcmp(s, "random") == 0)
		*vp = ISOLATION_RANDOM;
	else if (strcmp(s, "read-uncommitted") == 0)
		*vp = ISOLATION_READ_UNCOMMITTED;
	else if (strcmp(s, "read-committed") == 0)
		*vp = ISOLATION_READ_COMMITTED;
	else if (strcmp(s, "snapshot") == 0)
		*vp = ISOLATION_SNAPSHOT;
	else
		testutil_die(EINVAL, "illegal isolation configuration: %s", s);
}

/*
 * config_find
 *	Find a specific configuration entry.
 */
static CONFIG *
config_find(const char *s, size_t len)
{
	CONFIG *cp;

	for (cp = c; cp->name != NULL; ++cp) 
		if (strncmp(s, cp->name, len) == 0 && cp->name[len] == '\0')
			return (cp);

	fprintf(stderr,
	    "%s: %s: unknown configuration keyword\n", g.progname, s);
	config_error();
	exit(EXIT_FAILURE);
}

/*
 * config_is_perm
 *	Return if a specific configuration entry was permanently set.
 */
static int
config_is_perm(const char *s)
{
	CONFIG *cp;

	cp = config_find(s, strlen(s));
	return (F_ISSET(cp, C_PERM) ? 1 : 0);
}

/*
 * config_file_type --
 *	Return the file type as a string.
 */
static const char *
config_file_type(u_int type)
{
	switch (type) {
	case FIX:
		return ("fixed-length column-store");
	case VAR:
		return ("variable-length column-store");
	case ROW:
		return ("row-store");
	default:
		break;
	}
	return ("error: unknown file type");
}