bpo-41324 Add a minimal decimal capsule API (#21519)

1 files changed, 74 insertions, 0 deletions

diff --git a/Modules/_decimal/tests/deccheck.py b/Modules/_decimal/tests/deccheck.py
index 5d9179e..15f104d 100644
--- a/Modules/_decimal/tests/deccheck.py
+++ b/Modules/_decimal/tests/deccheck.py
@@ -49,6 +49,9 @@ from randdec import unary_optarg, binary_optarg, ternary_optarg
 from formathelper import rand_format, rand_locale
 from _pydecimal import _dec_from_triple
 
+from _testcapi import decimal_as_triple
+from _testcapi import decimal_from_triple
+
 C = import_fresh_module('decimal', fresh=['_decimal'])
 P = import_fresh_module('decimal', blocked=['_decimal'])
 EXIT_STATUS = 0
@@ -154,6 +157,45 @@ TernaryRestricted = ['__pow__', 'context.power']
 
 
 # ======================================================================
+#                            Triple tests
+# ======================================================================
+
+def c_as_triple(dec):
+    sign, hi, lo, exp = decimal_as_triple(dec)
+
+    coeff = hi * 2**64 + lo
+    return (sign, coeff, exp)
+
+def c_from_triple(triple):
+    sign, coeff, exp = triple
+
+    hi = coeff // 2**64
+    lo = coeff % 2**64
+    return decimal_from_triple((sign, hi, lo, exp))
+
+def p_as_triple(dec):
+    sign, digits, exp = dec.as_tuple()
+
+    s = "".join(str(d) for d in digits)
+    coeff = int(s) if s else 0
+
+    if coeff < 0 or coeff >= 2**128:
+        raise ValueError("value out of bounds for a uint128 triple");
+
+    return (sign, coeff, exp)
+
+def p_from_triple(triple):
+    sign, coeff, exp = triple
+
+    if coeff < 0 or coeff >= 2**128:
+        raise ValueError("value out of bounds for a uint128 triple");
+
+    digits = tuple(int(c) for c in str(coeff))
+
+    return P.Decimal((sign, digits, exp))
+
+
+# ======================================================================
 #                            Unified Context
 # ======================================================================
 
@@ -846,12 +888,44 @@ def verify(t, stat):
         t.presults.append(str(t.rp.imag))
         t.presults.append(str(t.rp.real))
 
+        ctriple = None
+        if t.funcname not in ['__radd__', '__rmul__']: # see skip handler
+            try:
+                ctriple = c_as_triple(t.rc)
+            except ValueError:
+                try:
+                    ptriple = p_as_triple(t.rp)
+                except ValueError:
+                    pass
+                else:
+                    raise RuntimeError("ValueError not raised")
+            else:
+                cres = c_from_triple(ctriple)
+                t.cresults.append(ctriple)
+                t.cresults.append(str(cres))
+
+                ptriple = p_as_triple(t.rp)
+                pres = p_from_triple(ptriple)
+                t.presults.append(ptriple)
+                t.presults.append(str(pres))
+
         if t.with_maxcontext and isinstance(t.rmax, C.Decimal):
             t.maxresults.append(t.rmax.to_eng_string())
             t.maxresults.append(t.rmax.as_tuple())
             t.maxresults.append(str(t.rmax.imag))
             t.maxresults.append(str(t.rmax.real))
 
+            if ctriple is not None:
+                # NaN payloads etc. depend on precision and clamp.
+                if all_nan(t.rc) and all_nan(t.rmax):
+                    t.maxresults.append(ctriple)
+                    t.maxresults.append(str(cres))
+                else:
+                    maxtriple = c_as_triple(t.rmax)
+                    maxres = c_from_triple(maxtriple)
+                    t.maxresults.append(maxtriple)
+                    t.maxresults.append(str(maxres))
+
         nc = t.rc.number_class().lstrip('+-s')
         stat[nc] += 1
     else: