1 files changed, 95 insertions, 0 deletions
diff --git a/klippy/chelper.py b/klippy/chelper.py
new file mode 100644
index 00000000..99ec3f4f
--- /dev/null
+++ b/klippy/chelper.py
@@ -0,0 +1,95 @@
+# Wrapper around C helper code
+#
+# Copyright (C) 2016  Kevin O'Connor <kevin@koconnor.net>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
+import os, logging
+import cffi
+
+COMPILE_CMD = "gcc -Wall -g -O -shared -fPIC -o %s %s"
+SOURCE_FILES = ['stepcompress.c', 'serialqueue.c']
+DEST_LIB = "c_helper.so"
+OTHER_FILES = ['list.h', 'serialqueue.h']
+
+defs_stepcompress = """
+    struct stepcompress *stepcompress_alloc(uint32_t max_error
+        , uint32_t queue_step_msgid, uint32_t oid);
+    void stepcompress_push(struct stepcompress *sc, double step_clock);
+    double stepcompress_push_factor(struct stepcompress *sc
+        , double steps, double step_offset
+        , double clock_offset, double factor);
+    double stepcompress_push_sqrt(struct stepcompress *sc
+        , double steps, double step_offset
+        , double clock_offset, double sqrt_offset, double factor);
+    void stepcompress_reset(struct stepcompress *sc, uint64_t last_step_clock);
+    void stepcompress_queue_msg(struct stepcompress *sc
+        , uint32_t *data, int len);
+    uint32_t stepcompress_get_errors(struct stepcompress *sc);
+
+    struct steppersync *steppersync_alloc(struct serialqueue *sq
+        , struct stepcompress **sc_list, int sc_num, int move_num);
+    void steppersync_flush(struct steppersync *ss, uint64_t move_clock);
+"""
+
+defs_serialqueue = """
+    #define MESSAGE_MAX 64
+    struct pull_queue_message {
+        uint8_t msg[MESSAGE_MAX];
+        int len;
+        double sent_time, receive_time;
+    };
+
+    struct serialqueue *serialqueue_alloc(int serial_fd, double baud_adjust
+        , int write_only);
+    void serialqueue_exit(struct serialqueue *sq);
+    struct command_queue *serialqueue_alloc_commandqueue(void);
+    void serialqueue_send(struct serialqueue *sq, struct command_queue *cq
+        , uint8_t *msg, int len, uint64_t min_clock, uint64_t req_clock);
+    void serialqueue_encode_and_send(struct serialqueue *sq
+        , struct command_queue *cq, uint32_t *data, int len
+        , uint64_t min_clock, uint64_t req_clock);
+    void serialqueue_pull(struct serialqueue *sq, struct pull_queue_message *pqm);
+    void serialqueue_set_clock_est(struct serialqueue *sq, double est_clock
+        , double last_ack_time, uint64_t last_ack_clock);
+    void serialqueue_flush_ready(struct serialqueue *sq);
+    void serialqueue_get_stats(struct serialqueue *sq, char *buf, int len);
+    int serialqueue_extract_old(struct serialqueue *sq, int sentq
+        , struct pull_queue_message *q, int max);
+"""
+
+# Return the list of file modification times
+def get_mtimes(srcdir, filelist):
+    out = []
+    for filename in filelist:
+        pathname = os.path.join(srcdir, filename)
+        try:
+            t = os.path.getmtime(pathname)
+        except os.error:
+            continue
+        out.append(t)
+    return out
+
+# Check if the code needs to be compiled
+def check_build_code(srcdir):
+    src_times = get_mtimes(srcdir, SOURCE_FILES + OTHER_FILES)
+    obj_times = get_mtimes(srcdir, [DEST_LIB])
+    if not obj_times or max(src_times) > min(obj_times):
+        logging.info("Building C code module")
+        srcfiles = [os.path.join(srcdir, fname) for fname in SOURCE_FILES]
+        destlib = os.path.join(srcdir, DEST_LIB)
+        os.system(COMPILE_CMD % (destlib, ' '.join(srcfiles)))
+
+FFI_main = None
+FFI_lib = None
+
+# Return the Foreign Function Interface api to the caller
+def get_ffi():
+    global FFI_main, FFI_lib
+    if FFI_lib is None:
+        srcdir = os.path.dirname(os.path.realpath(__file__))
+        check_build_code(srcdir)
+        FFI_main = cffi.FFI()
+        FFI_main.cdef(defs_stepcompress)
+        FFI_main.cdef(defs_serialqueue)
+        FFI_lib = FFI_main.dlopen(os.path.join(srcdir, DEST_LIB))
+    return FFI_main, FFI_lib