4 files changed, 115 insertions, 0 deletions
diff --git a/util/array.c b/util/array.c
new file mode 100644
index 0000000..ec16a7b
--- /dev/null
+++ b/util/array.c
@@ -0,0 +1,40 @@
+#include "util/array.h"
+#include <assert.h>
+#include <string.h>
+
+void array_remove_at(struct wl_array *arr, size_t offset, size_t size) {
+	assert(arr->size >= offset + size);
+
+	char *data = arr->data;
+	memmove(&data[offset], &data[offset + size], arr->size - offset - size);
+	arr->size -= size;
+}
+
+bool array_realloc(struct wl_array *arr, size_t size) {
+	// If the size is less than 1/4th of the allocation size, we shrink it.
+	// 1/4th is picked to provide hysteresis, without which an array with size
+	// arr->alloc would constantly reallocate if an element is added and then
+	// removed continously.
+	size_t alloc;
+	if (arr->alloc > 0 && size > arr->alloc / 4) {
+		alloc = arr->alloc;
+	} else {
+		alloc = 16;
+	}
+
+	while (alloc < size) {
+		alloc *= 2;
+	}
+
+	if (alloc == arr->alloc) {
+		return true;
+	}
+
+	void *data = realloc(arr->data, alloc);
+	if (data == NULL) {
+		return false;
+	}
+	arr->data = data;
+	arr->alloc = alloc;
+	return true;
+}
diff --git a/util/env.c b/util/env.c
new file mode 100644
index 0000000..b0a9efd
--- /dev/null
+++ b/util/env.c
@@ -0,0 +1,38 @@
+#include <stdlib.h>
+#include <string.h>
+#include <wlr/util/log.h>
+#include "util/env.h"
+
+bool env_parse_bool(const char *option) {
+	const char *env = getenv(option);
+	if (env) {
+		wlr_log(WLR_INFO, "Loading %s option: %s", option, env);
+	}
+
+	if (!env || strcmp(env, "0") == 0) {
+		return false;
+	} else if (strcmp(env, "1") == 0) {
+		return true;
+	}
+
+	wlr_log(WLR_ERROR, "Unknown %s option: %s", option, env);
+	return false;
+}
+
+ssize_t env_parse_switch(const char *option, const char **switches) {
+	const char *env = getenv(option);
+	if (env) {
+		wlr_log(WLR_INFO, "Loading %s option: %s", option, env);
+	} else {
+		return 0;
+	}
+
+	for (ssize_t i = 0; switches[i]; i++) {
+		if (strcmp(env, switches[i]) == 0) {
+			return i;
+		}
+	}
+
+	wlr_log(WLR_ERROR, "Unknown %s option: %s", option, env);
+	return 0;
+}
diff --git a/util/meson.build b/util/meson.build
new file mode 100644
index 0000000..b54835c
--- /dev/null
+++ b/util/meson.build
@@ -0,0 +1,5 @@
+wlr_files += files(
+	'array.c',
+	'env.c',
+	'time.c',
+)
diff --git a/util/time.c b/util/time.c
new file mode 100644
index 0000000..06e42b4
--- /dev/null
+++ b/util/time.c
@@ -0,0 +1,32 @@
+#define _POSIX_C_SOURCE 200809L
+#include <stdint.h>
+#include <time.h>
+
+#include "util/time.h"
+
+static const long NSEC_PER_SEC = 1000000000;
+
+int64_t timespec_to_msec(const struct timespec *a) {
+	return (int64_t)a->tv_sec * 1000 + a->tv_nsec / 1000000;
+}
+
+void timespec_from_nsec(struct timespec *r, int64_t nsec) {
+	r->tv_sec = nsec / NSEC_PER_SEC;
+	r->tv_nsec = nsec % NSEC_PER_SEC;
+}
+
+uint32_t get_current_time_msec(void) {
+	struct timespec now;
+	clock_gettime(CLOCK_MONOTONIC, &now);
+	return timespec_to_msec(&now);
+}
+
+void timespec_sub(struct timespec *r, const struct timespec *a,
+		const struct timespec *b) {
+	r->tv_sec = a->tv_sec - b->tv_sec;
+	r->tv_nsec = a->tv_nsec - b->tv_nsec;
+	if (r->tv_nsec < 0) {
+		r->tv_sec--;
+		r->tv_nsec += NSEC_PER_SEC;
+	}
+}