make ldetect 3x faster (and even faster on machines quite quite a lot

of devices such as servers)

(modalias_init) split it out of modalias_resolve_module()

(modalias_cleanup) move libkmod related cleanups here

(hid_probe,find_modules_through_aliases) only initialize libkmod once
(which reduces user time from 0.26 to 0.08s & elapsed time from 0.28 to
0.9s)

(backported from trunk)

5 files changed, 38 insertions, 27 deletions

diff --git a/NEWS b/NEWS
index 8631071..e659629 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,5 @@
+- make ldetect 3x faster
+
 Version 0.12.1 - 19 January 2012, Thierry Vignaud
 
 - do not ignore /etc/modprobe.d/*
diff --git a/common.h b/common.h
index e6f927d..cf99de2 100644
--- a/common.h
+++ b/common.h
@@ -19,8 +19,9 @@ typedef enum {
 
 extern int pciusb_find_modules(struct pciusb_entries *entries, const char *fpciusbtable, const descr_lookup, int is_pci) NON_EXPORTED;
 extern void pciusb_initialize(struct pciusb_entry *e) NON_EXPORTED;
-extern char *modalias_resolve_module(const char *modalias) NON_EXPORTED;
-extern void modalias_cleanup(void) NON_EXPORTED;
+extern struct kmod_ctx* modalias_init() NON_EXPORTED;
+extern char *modalias_resolve_module(struct kmod_ctx *ctx, const char *modalias) NON_EXPORTED;
+extern void modalias_cleanup(struct kmod_ctx *ctx) NON_EXPORTED;
 
 #define MAX_DEVICES 100
 #define BUF_SIZE 512
diff --git a/hid.c b/hid.c
index 5671a66..b9b5c9d 100644
--- a/hid.c
+++ b/hid.c
@@ -4,6 +4,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <libkmod.h>
 
 #include "libsysfs.h"
 #include "libldetect.h"
@@ -79,7 +80,7 @@ static void add_entry(struct hid_entries *entry_list, char *name, char *module)
 	}
 }
 
-static void parse_device(struct hid_entries *entries, const char *dev)
+static void parse_device(struct kmod_ctx *ctx, struct hid_entries *entries, const char *dev)
 {
 	char keyfile[SYSFS_PATH_MAX];
 	char *modalias;
@@ -111,12 +112,11 @@ static void parse_device(struct hid_entries *entries, const char *dev)
 	else 
 		device_name = strdup("HID Device");
 
-	modname = modalias_resolve_module(modalias);
+	modname = modalias_resolve_module(ctx, modalias);
 	free(modalias);
 	DEBUG("%s: module name is [%s]\n", HID_BUS_NAME, modname);
 	if (modname != NULL) 
 		add_entry(entries, device_name, modname);
-	modalias_cleanup();
 }
 
 
@@ -125,6 +125,7 @@ struct hid_entries hid_probe(void)
 	DIR *dir;
 	struct dirent *dent;
 	struct hid_entries entry_list = {NULL, 0};
+	struct kmod_ctx *ctx = modalias_init();
 
 	dir = opendir(sysfs_hid_path);
 	if (dir == NULL)
@@ -134,10 +135,11 @@ struct hid_entries hid_probe(void)
 		if (dent->d_name[0] == '.')
 			continue;
 		DEBUG("%s: device found %s\n", HID_BUS_NAME, dent->d_name);
-		parse_device(&entry_list, dent->d_name);
+		parse_device(ctx, &entry_list, dent->d_name);
 	}
 
 end_probe:
+	modalias_cleanup(ctx);
 	if (dir)
 		closedir(dir);
 
diff --git a/modalias.c b/modalias.c
index a5b12e2..029617e 100644
--- a/modalias.c
+++ b/modalias.c
@@ -24,7 +24,7 @@ static void get_version(void) {
 }
 
 
-char*dirname;
+char *dirname, *dkms_file;
 
 static void set_default_alias_file(void) {
 	struct utsname rel_buf;
@@ -51,11 +51,8 @@ static void set_default_alias_file(void) {
 	}
 }
 
-char *modalias_resolve_module(const char *modalias) {
+struct kmod_ctx* modalias_init() {
         struct kmod_ctx *ctx;
-	struct kmod_list *l, *list = NULL;
-	int err;
-	char* dkms_file,  *str = NULL;
 
 	if (!aliasdefault)
 		set_default_alias_file();
@@ -78,11 +75,18 @@ char *modalias_resolve_module(const char *modalias) {
 	ctx = kmod_new(dirname, alias_filelist);
 	if (!ctx) {
 		fputs("Error: kmod_new() failed!\n", stderr);
-		goto exit;
+		free(dkms_file);
+		kmod_unref(ctx);
+		ctx = NULL;
 	}
 	kmod_load_resources(ctx);
+	return ctx;
+}
 
-	err = kmod_module_new_from_lookup(ctx, modalias, &list);
+char *modalias_resolve_module(struct kmod_ctx *ctx, const char *modalias) {
+	struct kmod_list *l, *list = NULL;
+	char *str = NULL;
+	int err = kmod_module_new_from_lookup(ctx, modalias, &list);
 	if (err < 0)
 		goto exit;
 
@@ -112,12 +116,12 @@ char *modalias_resolve_module(const char *modalias) {
 	kmod_module_unref_list(list);
 
 exit:
-	free(dkms_file);
-	kmod_unref(ctx);
 	return str;
 }
 
-void modalias_cleanup(void) {
+void modalias_cleanup(struct kmod_ctx *ctx) {
     ifree(aliasdefault);
     ifree(version);
+    free(dkms_file);
+    kmod_unref(ctx);
 }
diff --git a/pciusb.c b/pciusb.c
index 9f7f4d5..350b092 100644
--- a/pciusb.c
+++ b/pciusb.c
@@ -9,9 +9,10 @@
 #include <stdlib.h>
 #include <string.h>
 #include <dirent.h>
+#include <libkmod.h>
 #include "common.h"
 
-static void set_modules_from_modalias_file(struct pciusb_entry *e, char *modalias_path) {
+static void set_modules_from_modalias_file(struct kmod_ctx *ctx, struct pciusb_entry *e, char *modalias_path) {
 	FILE *file;
 	file = fopen(modalias_path, "r");
 	if (file) {
@@ -28,7 +29,7 @@ static void set_modules_from_modalias_file(struct pciusb_entry *e, char *modalia
 			modalias[size-1] = 0;
 
 		ifree(e->module);
-		e->module = modalias_resolve_module(modalias);
+		e->module = modalias_resolve_module(ctx, modalias);
 		free(modalias);
 	} else {
 		fprintf(stderr, "Unable to read modalias from %s\n", modalias_path);
@@ -36,16 +37,16 @@ static void set_modules_from_modalias_file(struct pciusb_entry *e, char *modalia
 	}
 }
 
-static void find_pci_modules_through_aliases(struct pciusb_entry *e) {
+static void find_pci_modules_through_aliases(struct kmod_ctx *ctx, struct pciusb_entry *e) {
 	char *modalias_path;
 	asprintf(&modalias_path,
 		 "/sys/bus/pci/devices/%04x:%02x:%02x.%x/modalias",
 		 e->pci_domain, e->pci_bus, e->pci_device, e->pci_function);
-	set_modules_from_modalias_file(e, modalias_path);
+	set_modules_from_modalias_file(ctx, e, modalias_path);
 	free(modalias_path);
 }
 
-static void find_usb_modules_through_aliases(struct pciusb_entry *e) {
+static void find_usb_modules_through_aliases(struct kmod_ctx *ctx, struct pciusb_entry *e) {
 	char *usb_prefix, *sysfs_path;
 	DIR *dir;
 	struct dirent *dent;
@@ -63,7 +64,7 @@ static void find_usb_modules_through_aliases(struct pciusb_entry *e) {
 		    !strncmp(usb_prefix, dent->d_name, strlen(usb_prefix))) {
 			char *modalias_path;
 			asprintf(&modalias_path, "%s/%s/modalias", sysfs_path, dent->d_name);
-			set_modules_from_modalias_file(e, modalias_path);
+			set_modules_from_modalias_file(ctx, e, modalias_path);
 			free(modalias_path);
 			/* maybe we would need a "other_modules" field in pciusb_entry 
 			   to list modules from all USB interfaces */
@@ -77,26 +78,27 @@ end:
 	free(usb_prefix);
 }
 
-static void find_modules_through_aliases_one(const char *bus, struct pciusb_entry *e) {
+static void find_modules_through_aliases_one(struct kmod_ctx *ctx, const char *bus, struct pciusb_entry *e) {
 	if (!strcmp("pci", bus)) {
-		find_pci_modules_through_aliases(e);
+		find_pci_modules_through_aliases(ctx, e);
 	} else if (!strcmp("usb", bus)) {
-		find_usb_modules_through_aliases(e);
+		find_usb_modules_through_aliases(ctx, e);
 	}
 }
 
 static void find_modules_through_aliases(const char *bus, struct pciusb_entries *entries) {
 	unsigned int i;
+	struct kmod_ctx *ctx = modalias_init();
 	for (i = 0; i < entries->nb; i++) {
 		struct pciusb_entry *e = &entries->entries[i];
 
 		// No special case found in pcitable ? Then lookup modalias for PCI devices
 		if (e->module && strcmp(e->module, "unknown"))
 			continue;
-		find_modules_through_aliases_one(bus, e);
+		find_modules_through_aliases_one(ctx, bus, e);
 	}
 
-	modalias_cleanup();
+	modalias_cleanup(ctx);
 }
 
 extern int pciusb_find_modules(struct pciusb_entries *entries, const char *fpciusbtable, const descr_lookup descr_lookup, int is_pci) {