Set the max_htlc based on local balance

README.md

@@ -203,6 +203,7 @@ All strategies (except the ignore strategy) will apply the following properties
 | **min_htlc_msat** | Minimum size (in msat) of HTLC to allow | # msat |
 | **max_htlc_msat** | Maximum size (in msat) of HTLC to allow | # msat |
 | **max_htlc_msat_ratio** | Maximum size of HTLC to allow as a fraction of total channel capacity | 0..1 |
+| **max_htlc_proportional_slices** | Maximum size of HTLC set proportionally to local balance with slices number of steps | # slices |
 | **time_lock_delta** | Time Lock Delta | # blocks |
 | **min_fee_ppm_delta** | Minimum change in fees (ppm) before updating channel | ppm delta |
 

charge_lnd/strategy.py

@@ -19,6 +19,17 @@ def call_strategy(*args, **kwargs):
         return call_strategy
     return register_strategy
 
+def calculate_slices(max_value, current_value, num_slices):
+    # Calculate the size of each slice
+    slice_size = max_value // num_slices
+
+    # Find the slice number containing the current_value
+    current_slice = min(current_value // slice_size, num_slices - 1)
+
+    # Determine the upper value of the slice closest to current without going over
+    slice_point = min((current_slice + 1) * slice_size - 1, max_value)
+
+    return slice_point
 
 class StrategyDelegate:
     STRATEGIES = {}
@@ -48,6 +59,11 @@ def execute(self, channel):
 
     def effective_max_htlc_msat(self, channel):
         result = self.policy.getint('max_htlc_msat')
+
+        slices = self.policy.getint('max_htlc_proportional_slices')
+        if slices:
+            result = calculate_slices(channel.capacity, channel.local_balance, slices)
+
         ratio = self.policy.getfloat('max_htlc_msat_ratio')
         if ratio:
             ratio = max(0,min(1,ratio))

examples/max-htlc-proportional.config

@@ -0,0 +1,24 @@
+# all channels max_htlc set to a value proportional to
+# local balance, with specified number of divisions
+# e.g.
+#      slices = 10
+#      channel_size = 1_000_000 sats
+#      max_htlc values:
+#      100_000, 200_000, 300_000, 400_000, 500_000
+#      600_000, 700_000, 800_000, 900_000, 1_000_000
+#
+#      slices = 2
+#      channel_size = 800_000_sats
+#      max_htlc values:
+#      400_000, 800_000
+#
+# Rationale: avoid insufficient local balance failures
+# to improve your node's reputation of successful forwarding.
+
+[default]
+strategy = ignore
+
+[proportional_htlc]
+chan.max_local_balance = 30_000_000
+strategy = static
+max_htlc_proportional_slices = 6