Support "destructive" compression to save memory

[wimlib] / src / compress.c

diff --git a/src/compress.c b/src/compress.c
index 47026e368d0b256afd1829fdbdc01a49e99be5b9..ff28ebc0f79d915701a9fdb0ef68ac47e3fbda8c 100644 (file)
--- a/src/compress.c
+++ b/src/compress.c
@@ -81,12 +81,19 @@ wimlib_get_compressor_needed_memory(enum wimlib_compression_type ctype,
                                    size_t max_block_size,
                                    unsigned int compression_level)
 {
+       bool destructive;
        const struct compressor_ops *ops;
        u64 size;
 
+       destructive = (compression_level & WIMLIB_COMPRESSOR_FLAG_DESTRUCTIVE);
+       compression_level &= ~WIMLIB_COMPRESSOR_FLAG_DESTRUCTIVE;
+
        if (!compressor_ctype_valid(ctype))
                return 0;
 
+       if (compression_level > 0xFFFFFF)
+               return 0;
+
        if (max_block_size == 0)
                return 0;
 
@@ -98,7 +105,8 @@ wimlib_get_compressor_needed_memory(enum wimlib_compression_type ctype,
                compression_level = DEFAULT_COMPRESSION_LEVEL;
 
        if (ops->get_needed_memory) {
-               size = ops->get_needed_memory(max_block_size, compression_level);
+               size = ops->get_needed_memory(max_block_size, compression_level,
+                                             destructive);
 
                /* 0 is never valid and indicates an invalid max_block_size.  */
                if (size == 0)
@@ -115,11 +123,18 @@ wimlib_create_compressor(enum wimlib_compression_type ctype,
                         unsigned int compression_level,
                         struct wimlib_compressor **c_ret)
 {
+       bool destructive;
        struct wimlib_compressor *c;
 
+       destructive = (compression_level & WIMLIB_COMPRESSOR_FLAG_DESTRUCTIVE);
+       compression_level &= ~WIMLIB_COMPRESSOR_FLAG_DESTRUCTIVE;
+
        if (!compressor_ctype_valid(ctype))
                return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
 
+       if (compression_level > 0xFFFFFF)
+               return WIMLIB_ERR_INVALID_PARAM;
+
        if (c_ret == NULL)
                return WIMLIB_ERR_INVALID_PARAM;
 
@@ -143,6 +158,7 @@ wimlib_create_compressor(enum wimlib_compression_type ctype,
 
                ret = c->ops->create_compressor(max_block_size,
                                                compression_level,
+                                               destructive,
                                                &c->private);
                if (ret) {
                        FREE(c);