I have created a small wrapper for the Brotli compression format: [L1 ]
The code uses critcl:
package require Tcl 8.4
package require critcl 3.1
critcl::buildrequirement {
package require critcl::class
}
# critcl::config language c++
critcl::license {Georgios Petasis} {BSD licensed}
critcl::summary {Stack objects for Tcl.}
critcl::description {
This package implements stack objects
for Tcl. It uses the abstract data type
provided by package 'cstack' for actual
storage and operations.
}
critcl::subject brotli
::critcl::clibraries -lbrotlidec -lbrotlienc
critcl::class::define ::brotli {
# include vector
include brotli/decode.h
include brotli/encode.h
insvariable BrotliEncoderMode mode {} {
instance->mode=(BrotliEncoderMode) BROTLI_DEFAULT_MODE;
}
insvariable int lgwin {} {instance->lgwin = BROTLI_DEFAULT_WINDOW;}
insvariable int lgblock {} {instance->lgblock = -1;}
insvariable int quality {} {instance->quality = BROTLI_DEFAULT_QUALITY;}
method compress command {} {
int length;
size_t out_len;
const uint8_t *input;
BrotliEncoderState* state;
uint8_t *output;
int status;
if (objc != 3) {
Tcl_WrongNumArgs (interp, 2, objv, "binary_content_to_compress");
return TCL_ERROR;
}
Tcl_ResetResult(interp);
input = Tcl_GetByteArrayFromObj(objv[2], &length);
if (!length) return TCL_OK;
/* Get an estimation about the output buffer... */
out_len = BrotliEncoderMaxCompressedSize(length);
if (out_len == 0) {
Tcl_SetResult(interp, "needed output buffer too large to encode input",
TCL_STATIC);
return TCL_ERROR;
}
output = (uint8_t *) ckalloc(sizeof(uint8_t) * (out_len+1));
if (output == NULL) {
Tcl_SetResult(interp, "cannot allocate needed output buffer",
TCL_STATIC);
return TCL_ERROR;
}
/* Compress... */
status = BrotliEncoderCompress(instance->quality, instance->lgwin,
instance->mode, length, input,
&out_len, output);
if (status) {
Tcl_SetObjResult(interp,
Tcl_NewByteArrayObj((unsigned char *) output, out_len));
status = TCL_OK;
} else {
Tcl_SetResult(interp, "cannot compress input", TCL_STATIC);
status = TCL_ERROR;
}
ckfree((char *) output);
return status;
};# compress
method decompress command {} {
Tcl_DString output;
int length;
size_t input_len;
const uint8_t *input;
int status;
if (objc != 3) {
Tcl_WrongNumArgs (interp, 2, objv, "binary_content_to_decode");
return TCL_ERROR;
}
Tcl_ResetResult(interp);
input = Tcl_GetByteArrayFromObj(objv[2], &length);
if (!length) return TCL_OK;
Tcl_DStringInit(&output);
BrotliDecoderState* state = BrotliDecoderCreateInstance(0, 0, 0);
BrotliDecoderResult result = BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT;
input_len = length;
while (result == BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT) {
size_t available_out = 0;
result = BrotliDecoderDecompressStream(state, &input_len, &input,
&available_out, 0, 0);
const uint8_t* next_out = BrotliDecoderTakeOutput(state,
&available_out);
if (available_out != 0) {
Tcl_DStringAppend(&output, next_out, available_out);
}
}
status = result == BROTLI_DECODER_RESULT_SUCCESS;
BrotliDecoderDestroyInstance(state);
if (status) {
Tcl_SetObjResult(interp,
Tcl_NewByteArrayObj(Tcl_DStringValue(&output),
Tcl_DStringLength(&output)));
status = TCL_OK;
} else {
BrotliDecoderErrorCode code = BrotliDecoderGetErrorCode(state);
Tcl_SetResult(interp, (char *) BrotliDecoderErrorString(code),
TCL_DYNAMIC);
status = TCL_ERROR;
}
Tcl_DStringFree(&output);
return status;
};# decompress
method decoder_version command {} {
if (objc != 2) {
Tcl_WrongNumArgs (interp, 2, objv, NULL);
return TCL_ERROR;
}
Tcl_SetObjResult(interp, Tcl_NewWideIntObj(BrotliDecoderVersion()));
return TCL_OK;
};# decoder_version
method encoder_version command {} {
if (objc != 2) {
Tcl_WrongNumArgs (interp, 2, objv, NULL);
return TCL_ERROR;
}
Tcl_SetObjResult(interp, Tcl_NewWideIntObj(BrotliEncoderVersion()));
return TCL_OK;
};# encoder_version
}
package provide brotli 1.0You can generate the package by saving the code in a file named "brotli.tcl" and then execute:
critcl -pkg brotli.tcl