Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 241 insertions, 0 deletions

diff --git a/qobject/qnum.c b/qobject/qnum.c
new file mode 100644
index 000000000..5dd66938d
--- /dev/null
+++ b/qobject/qnum.c
@@ -0,0 +1,241 @@
+/*
+ * QNum Module
+ *
+ * Copyright (C) 2009 Red Hat Inc.
+ *
+ * Authors:
+ *  Luiz Capitulino <lcapitulino@redhat.com>
+ *  Anthony Liguori <aliguori@us.ibm.com>
+ *  Marc-André Lureau <marcandre.lureau@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/qmp/qnum.h"
+#include "qobject-internal.h"
+
+/**
+ * qnum_from_int(): Create a new QNum from an int64_t
+ *
+ * Return strong reference.
+ */
+QNum *qnum_from_int(int64_t value)
+{
+    QNum *qn = g_new(QNum, 1);
+
+    qobject_init(QOBJECT(qn), QTYPE_QNUM);
+    qn->kind = QNUM_I64;
+    qn->u.i64 = value;
+
+    return qn;
+}
+
+/**
+ * qnum_from_uint(): Create a new QNum from an uint64_t
+ *
+ * Return strong reference.
+ */
+QNum *qnum_from_uint(uint64_t value)
+{
+    QNum *qn = g_new(QNum, 1);
+
+    qobject_init(QOBJECT(qn), QTYPE_QNUM);
+    qn->kind = QNUM_U64;
+    qn->u.u64 = value;
+
+    return qn;
+}
+
+/**
+ * qnum_from_double(): Create a new QNum from a double
+ *
+ * Return strong reference.
+ */
+QNum *qnum_from_double(double value)
+{
+    QNum *qn = g_new(QNum, 1);
+
+    qobject_init(QOBJECT(qn), QTYPE_QNUM);
+    qn->kind = QNUM_DOUBLE;
+    qn->u.dbl = value;
+
+    return qn;
+}
+
+/**
+ * qnum_get_try_int(): Get an integer representation of the number
+ *
+ * Return true on success.
+ */
+bool qnum_get_try_int(const QNum *qn, int64_t *val)
+{
+    switch (qn->kind) {
+    case QNUM_I64:
+        *val = qn->u.i64;
+        return true;
+    case QNUM_U64:
+        if (qn->u.u64 > INT64_MAX) {
+            return false;
+        }
+        *val = qn->u.u64;
+        return true;
+    case QNUM_DOUBLE:
+        return false;
+    }
+
+    assert(0);
+    return false;
+}
+
+/**
+ * qnum_get_int(): Get an integer representation of the number
+ *
+ * assert() on failure.
+ */
+int64_t qnum_get_int(const QNum *qn)
+{
+    int64_t val;
+    bool success = qnum_get_try_int(qn, &val);
+    assert(success);
+    return val;
+}
+
+/**
+ * qnum_get_uint(): Get an unsigned integer from the number
+ *
+ * Return true on success.
+ */
+bool qnum_get_try_uint(const QNum *qn, uint64_t *val)
+{
+    switch (qn->kind) {
+    case QNUM_I64:
+        if (qn->u.i64 < 0) {
+            return false;
+        }
+        *val = qn->u.i64;
+        return true;
+    case QNUM_U64:
+        *val = qn->u.u64;
+        return true;
+    case QNUM_DOUBLE:
+        return false;
+    }
+
+    assert(0);
+    return false;
+}
+
+/**
+ * qnum_get_uint(): Get an unsigned integer from the number
+ *
+ * assert() on failure.
+ */
+uint64_t qnum_get_uint(const QNum *qn)
+{
+    uint64_t val;
+    bool success = qnum_get_try_uint(qn, &val);
+    assert(success);
+    return val;
+}
+
+/**
+ * qnum_get_double(): Get a float representation of the number
+ *
+ * qnum_get_double() loses precision for integers beyond 53 bits.
+ */
+double qnum_get_double(QNum *qn)
+{
+    switch (qn->kind) {
+    case QNUM_I64:
+        return qn->u.i64;
+    case QNUM_U64:
+        return qn->u.u64;
+    case QNUM_DOUBLE:
+        return qn->u.dbl;
+    }
+
+    assert(0);
+    return 0.0;
+}
+
+char *qnum_to_string(QNum *qn)
+{
+    switch (qn->kind) {
+    case QNUM_I64:
+        return g_strdup_printf("%" PRId64, qn->u.i64);
+    case QNUM_U64:
+        return g_strdup_printf("%" PRIu64, qn->u.u64);
+    case QNUM_DOUBLE:
+        /* 17 digits suffice for IEEE double */
+        return g_strdup_printf("%.17g", qn->u.dbl);
+    }
+
+    assert(0);
+    return NULL;
+}
+
+/**
+ * qnum_is_equal(): Test whether the two QNums are equal
+ *
+ * Negative integers are never considered equal to unsigned integers,
+ * but positive integers in the range [0, INT64_MAX] are considered
+ * equal independently of whether the QNum's kind is i64 or u64.
+ *
+ * Doubles are never considered equal to integers.
+ */
+bool qnum_is_equal(const QObject *x, const QObject *y)
+{
+    QNum *num_x = qobject_to(QNum, x);
+    QNum *num_y = qobject_to(QNum, y);
+
+    switch (num_x->kind) {
+    case QNUM_I64:
+        switch (num_y->kind) {
+        case QNUM_I64:
+            /* Comparison in native int64_t type */
+            return num_x->u.i64 == num_y->u.i64;
+        case QNUM_U64:
+            /* Implicit conversion of x to uin64_t, so we have to
+             * check its sign before */
+            return num_x->u.i64 >= 0 && num_x->u.i64 == num_y->u.u64;
+        case QNUM_DOUBLE:
+            return false;
+        }
+        abort();
+    case QNUM_U64:
+        switch (num_y->kind) {
+        case QNUM_I64:
+            return qnum_is_equal(y, x);
+        case QNUM_U64:
+            /* Comparison in native uint64_t type */
+            return num_x->u.u64 == num_y->u.u64;
+        case QNUM_DOUBLE:
+            return false;
+        }
+        abort();
+    case QNUM_DOUBLE:
+        switch (num_y->kind) {
+        case QNUM_I64:
+        case QNUM_U64:
+            return false;
+        case QNUM_DOUBLE:
+            /* Comparison in native double type */
+            return num_x->u.dbl == num_y->u.dbl;
+        }
+        abort();
+    }
+
+    abort();
+}
+
+/**
+ * qnum_destroy_obj(): Free all memory allocated by a
+ * QNum object
+ */
+void qnum_destroy_obj(QObject *obj)
+{
+    assert(obj != NULL);
+    g_free(qobject_to(QNum, obj));
+}