4 files changed, 130 insertions, 0 deletions
diff --git a/lib/include/arena.h b/lib/include/arena.h
new file mode 100644
index 0000000..fa1674b
--- /dev/null
+++ b/lib/include/arena.h
@@ -0,0 +1,28 @@
+#ifndef VL_ARENA_H_INCLUDED
+#define VL_ARENA_H_INCLUDED
+
+/* implements a basic arena allocator */
+
+#include <stddef.h>
+#include <stdarg.h>
+
+typedef struct vl__arena_tag vl_arena;
+
+/* returns NULL if an arena could not be allocated */
+vl_arena *vl_arena_new(size_t cap);
+
+/* aborts if the arena is overflowing */
+void *vl_arena_push(vl_arena *parena, size_t len);
+
+/* resets the arena (but does not free it) */
+void vl_arena_reset(vl_arena *parena);
+
+/* frees the arena */
+void vl_arena_free(vl_arena *parena);
+
+char *vl_arena_strdup(vl_arena *parena, const char *str);
+
+char *vl_arena_sprintf(vl_arena *parena, const char *fmt, ...);
+char *vl_arena_vsprintf(vl_arena *parena, const char *fmt, va_list ap);
+
+#endif /* include guard */
diff --git a/lib/include/log.h b/lib/include/log.h
new file mode 100644
index 0000000..a8549e0
--- /dev/null
+++ b/lib/include/log.h
@@ -0,0 +1,52 @@
+#include <stdio.h>
+#include <stdarg.h>
+
+#define LOG_TRACE 0u
+#define LOG_DEBUG 1u
+#define LOG_INFO  2u
+#define LOG_WARN  3u
+#define LOG_ERROR 4u
+
+void vl_log_setlevel(unsigned level);
+
+void vl_logv(unsigned level, const char *fmt, va_list args);
+void vl_log(unsigned level, const char *fmt, ...) __attribute__((format(printf, 2, 3)));
+
+#ifndef LOG_MIN_LEVEL
+#define LOG_MIN_LEVEL LOG_TRACE
+#endif
+
+#if LOG_TRACE >= LOG_MIN_LEVEL
+#define LOG_TRACE_ENABLED
+#define vl_trace(...) vl_log(LOG_TRACE, __VA_ARGS__)
+#define vl_tracev(...) vl_logv(LOG_TRACE, __VA_ARGS__)
+#else
+#define vl_trace(...)
+#define vl_tracev(...)
+#endif
+
+#if LOG_DEBUG >= LOG_MIN_LEVEL
+#define LOG_DEBUG_ENABLED
+#define vl_debug(...) vl_log(LOG_DEBUG, __VA_ARGS__)
+#define vl_debugv(...) vl_logv(LOG_DEBUG, __VA_ARGS__)
+#else
+#define vl_debug(...)
+#define vl_debugv(...)
+#endif
+
+#if LOG_INFO >= LOG_MIN_LEVEL
+#define LOG_INFO_ENABLED
+#define vl_info(...) vl_log(LOG_INFO, __VA_ARGS__)
+#define vl_infov(...) vl_logv(LOG_INFO, __VA_ARGS__)
+#else
+#define vl_info(...)
+#define vl_infov(...)
+#endif
+
+#define LOG_WARN_ENABLED
+#define vl_warn(...) vl_log(LOG_WARN, __VA_ARGS__)
+#define vl_warnv(...) vl_logv(LOG_WARN, __VA_ARGS__)
+ 
+#define LOG_ERROR_ENABLED
+#define vl_error(...) vl_log(LOG_ERROR, __VA_ARGS__)
+#define vl_errorv(...) vl_logv(LOG_ERROR, __VA_ARGS__)
diff --git a/lib/include/net.h b/lib/include/net.h
new file mode 100644
index 0000000..d5f1482
--- /dev/null
+++ b/lib/include/net.h
@@ -0,0 +1,8 @@
+#ifndef VL_NET_H_INCLUDED
+#define VL_NET_H_INCLUDED
+
+#include "arena.h"
+
+int vl_net_ensure_cached(vl_arena *arena, const char *url, const char *target_path);
+
+#endif
diff --git a/lib/include/sha1.h b/lib/include/sha1.h
new file mode 100644
index 0000000..05cedd4
--- /dev/null
+++ b/lib/include/sha1.h
@@ -0,0 +1,42 @@
+#ifndef VL_SHA1_H_INCLUDED
+#define VL_SHA1_H_INCLUDED
+
+#include <stdint.h>
+#include <stddef.h>
+
+#define VL_SHA1_STATELEN_32    ( 5u) /* 160 bits / 32 (bits per int) = 5 ints */
+#define VL_SHA1_CHUNKLEN_BYTES (64u) /* 512 bits / 8 (bits per byte) = 64 bytes */
+
+#define VL_SHA1_DIGEST_BYTES (20u)
+#define VL_SHA1_DIGEST_HEX_STRLEN (VL_SHA1_DIGEST_BYTES << 1)
+
+typedef struct {
+  /* struct fields are internal (struct size is ABI doe) */
+  size_t vl_nchunk;
+  uint64_t vl_total;
+  uint32_t vl_state[VL_SHA1_STATELEN_32];
+  uint8_t vl_chunk[VL_SHA1_CHUNKLEN_BYTES];
+} vl_sha1_st;
+
+typedef uint8_t vl_sha1[VL_SHA1_DIGEST_BYTES];
+
+/* initializes a SHA1 state struct */
+void vl_sha1_init(vl_sha1_st *st);
+
+/* updates a SHA1 state struct with new data (must have been initialized with vl_sha1_init first) */
+void vl_sha1_update(vl_sha1_st *st, const void *data, size_t sz);
+
+/* finalizes a SHA1 state struct, writing the final digest to the second argument. the state struct
+ * is now invalid, and vl_sha1_init must be used on it again before it can be reused. */
+void vl_sha1_finalize(vl_sha1_st *st, vl_sha1 out);
+
+/* shortcut for hashing a buffer */
+void vl_sha1_buffer(vl_sha1 odigest, const void *data, size_t sz);
+
+/* converts digest bytes to a hex string (does NOT place a NUL byte) */
+void vl_sha1_encode(const vl_sha1 dig, char hex[VL_SHA1_DIGEST_HEX_STRLEN]);
+
+/* converts a hex string to digest bytes */
+int vl_sha1_decode(vl_sha1 odigest, const char hex[VL_SHA1_DIGEST_HEX_STRLEN]);
+
+#endif /* include guard */