utils.py: add compressed writemem

Signed-off-by: Sven Peter <sven@svenpeter.dev>

proxyclient/malloc.py

@@ -1,3 +1,5 @@
+from contextlib import contextmanager
+
 class Heap(object):
     def __init__(self, start, end, block=64):
         if start%block:
@@ -83,3 +85,11 @@ class Heap(object):
         print("Heap stats:")
         print(" In use: %8dkB"%(inuse * self.block // 1024))
         print(" Free:   %8dkB"%(free * self.block // 1024))
+
+    @contextmanager
+    def guarded_malloc(self, size):
+        addr = self.malloc(size)
+        try:
+            yield addr
+        finally:
+            self.free(addr)

proxyclient/utils.py

@@ -1,4 +1,4 @@
-import serial, os, struct, sys, time, json, os.path
+import serial, os, struct, sys, time, json, os.path, lzma
 from proxy import *
 from tgtypes import *
 import malloc
@@ -95,6 +95,19 @@ class ProxyUtils(object):
             raise ProxyError("Exception occurred")
         return ret
 
+    def compressed_writemem(self, dest, data, progress):
+        if not len(data):
+            return
+
+        payload = lzma.compress(data)
+        compressed_size = len(payload)
+
+        with self.heap.guarded_malloc(compressed_size) as compressed_addr:
+            self.iface.writemem(compressed_addr, payload, progress)
+            decompressed_size = self.proxy.xzdec(compressed_addr, compressed_size, dest, len(data))
+
+            assert decompressed_size == len(data)
+
 class RegMonitor(object):
     def __init__(self, utils):
         self.utils = utils