1 files changed, 77 insertions, 0 deletions
diff --git a/ossfuzz/fuzz_data_producer.c b/ossfuzz/fuzz_data_producer.c
new file mode 100644
index 0000000..670fbf5
--- /dev/null
+++ b/ossfuzz/fuzz_data_producer.c
@@ -0,0 +1,77 @@
+#include "fuzz_data_producer.h"
+
+struct FUZZ_dataProducer_s{
+  const uint8_t *data;
+  size_t size;
+};
+
+FUZZ_dataProducer_t* FUZZ_dataProducer_create(const uint8_t* data, size_t size) {
+  FUZZ_dataProducer_t* const producer = malloc(sizeof(FUZZ_dataProducer_t));
+
+  FUZZ_ASSERT(producer != NULL);
+
+  producer->data = data;
+  producer->size = size;
+  return producer;
+}
+
+void FUZZ_dataProducer_free(FUZZ_dataProducer_t *producer) { free(producer); }
+
+uint32_t FUZZ_dataProducer_retrieve32(FUZZ_dataProducer_t *producer) {
+    const uint8_t* data = producer->data;
+    const size_t size = producer->size;
+    if (size == 0) {
+        return 0;
+    } else if (size < 4) {
+        producer->size -= 1;
+        return (uint32_t)data[size - 1];
+    } else {
+        producer->size -= 4;
+        return *(data + size - 4);
+    }
+}
+
+uint32_t FUZZ_getRange_from_uint32(uint32_t seed, uint32_t min, uint32_t max)
+{
+    uint32_t range = max - min;
+    if (range == 0xffffffff) {
+      return seed;
+    }
+    return min + seed % (range + 1);
+}
+
+uint32_t FUZZ_dataProducer_range32(FUZZ_dataProducer_t* producer,
+    uint32_t min, uint32_t max)
+{
+    size_t const seed = FUZZ_dataProducer_retrieve32(producer);
+    return FUZZ_getRange_from_uint32(seed, min, max);
+}
+
+LZ4F_frameInfo_t FUZZ_dataProducer_frameInfo(FUZZ_dataProducer_t* producer)
+{
+    LZ4F_frameInfo_t info = LZ4F_INIT_FRAMEINFO;
+    info.blockSizeID = FUZZ_dataProducer_range32(producer, LZ4F_max64KB - 1, LZ4F_max4MB);
+    if (info.blockSizeID < LZ4F_max64KB) {
+        info.blockSizeID = LZ4F_default;
+    }
+    info.blockMode = FUZZ_dataProducer_range32(producer, LZ4F_blockLinked, LZ4F_blockIndependent);
+    info.contentChecksumFlag = FUZZ_dataProducer_range32(producer, LZ4F_noContentChecksum,
+                                           LZ4F_contentChecksumEnabled);
+    info.blockChecksumFlag = FUZZ_dataProducer_range32(producer, LZ4F_noBlockChecksum,
+                                         LZ4F_blockChecksumEnabled);
+    return info;
+}
+
+LZ4F_preferences_t FUZZ_dataProducer_preferences(FUZZ_dataProducer_t* producer)
+{
+    LZ4F_preferences_t prefs = LZ4F_INIT_PREFERENCES;
+    prefs.frameInfo = FUZZ_dataProducer_frameInfo(producer);
+    prefs.compressionLevel = FUZZ_dataProducer_range32(producer, 0, LZ4HC_CLEVEL_MAX + 3) - 3;
+    prefs.autoFlush = FUZZ_dataProducer_range32(producer, 0, 1);
+    prefs.favorDecSpeed = FUZZ_dataProducer_range32(producer, 0, 1);
+    return prefs;
+}
+
+size_t FUZZ_dataProducer_remainingBytes(FUZZ_dataProducer_t *producer){
+  return producer->size;
+}