第 93 章 正文解码：Content-Encoding 流式还原

#include <xrt/http_decode.h>

#include <stdio.h>



/* 把解码片段直接写到标准输出，实际网络代码可改为业务消费回调。 */
static bool printBody(xbytesview Data, ptr pData)
{
	FILE* pOutput = (FILE*)pData;

	return fwrite(Data.Data, 1, Data.Size, pOutput) == Data.Size;
}





















 */


/* 展示从 HTTP/1 Header 建立流式 gzip 解码器。 */
int main(void)
{
	static const uint8 Gzip[] = {
		0x1F, 0x8B, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00,
		0x02, 0xFF, 0xCB, 0x48, 0xCD, 0xC9, 0xC9, 0x57,
		0x48, 0xCE, 0xCF, 0x2D, 0x28, 0x4A, 0x2D, 0x2E,
		0x4E, 0x4D, 0x51, 0x28, 0xCF, 0x2F, 0xCA, 0x49,
		0x01, 0x00, 0xA1, 0x2D, 0x94, 0x53, 0x16, 0x00,
		0x00, 0x00
	};
	static const xhttpfield Fields[] = {
		{
			XRT_STR_INIT("Content-Encoding"),
			XRT_STR_INIT("gzip")
		}
	};
	xhttpdecode* pDecode = xrtHttpDecodeCreate(Fields, 1, NULL);
	bool bSuccess;

	if ( pDecode == NULL ) {
		return 1;
	}
	bSuccess = xrtHttpDecodeWrite(
		pDecode,
		(xbytesview){ Gzip, sizeof(Gzip) },
		true,
		printBody,
		stdout
	) && xrtHttpDecodeDone(pDecode);
	xrtHttpDecodeDestroy(pDecode);
	return bSuccess ? 0 : 1;
}

 */

#include <stdio.h>
#include <string.h>
#include <xrt.h>

/* 一段 gzip 压缩的 "identity-passthrough-check"。 */
static const uint8 arrGzip[46] = {
	0x1F, 0x8B, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x0A,
	0xCB, 0x4C, 0x49, 0xCD, 0x2B, 0xC9, 0x2C, 0xA9, 0xD4, 0x2D,
	0x48, 0x2C, 0x2E, 0x2E, 0xC9, 0x28, 0xCA, 0x2F, 0x4D, 0xCF,
	0xD0, 0x4D, 0xCE, 0x48, 0x4D, 0xCE, 0x06, 0x00, 0x9A, 0xFB,
	0x0B, 0xA2, 0x1A, 0x00, 0x00, 0x00
};

/* 输出回调：累计并比对内容。 */
typedef struct exampleout {
	size_t iBytes;
	char arrText[64];
} exampleout;

static bool exampleOutput(xbytesview Data, ptr pUserData)
{
	exampleout* pOut = (exampleout*)pUserData;

	if ( pOut->iBytes + Data.Size > sizeof(pOut->arrText) ) {
		return false;
	}
	memcpy(pOut->arrText + pOut->iBytes, Data.Data, Data.Size);
	pOut->iBytes += Data.Size;
	return true;
}

int main(void)
{
	xhttpdecodeconfig Compat;
	xhttpdecodeconfig Safe;
	xhttpdecode* pDecode = NULL;
	xhttpfield Fields[2];
	exampleout Out;
	int iResult = 1;

	/* ---- 两套配置 + gzip 字段建解码器。 ---- */
	xrtHttpDecodeConfigInit(&Compat);
	xrtHttpDecodeConfigInitSafe(&Safe);
	Fields[0].Name = XRT_STR_LITERAL("Content-Encoding");
	Fields[0].Value = XRT_STR_LITERAL("gzip");
	pDecode = xrtHttpDecodeCreate(Fields, 1u, &Compat);
	if ( (pDecode == NULL) ||
		/* 兼容配置不设输出上限；安全配置有显式上限。 */
		(Compat.OutputLimit != XHTTP_DECODE_OUTPUT_UNLIMITED) ||
		(Safe.OutputLimit == Compat.OutputLimit) ) {
		goto Cleanup;
	}
	printf("decode: config compat vs safe + create ok\n");

	/* ---- gzip 模式 + 输入输出计量。 ---- */
	memset(&Out, 0, sizeof(Out));
	if ( (xrtHttpDecodeMode(pDecode) != XHTTP_DECODE_CONTENT) ||
		!xrtHttpDecodeWrite(pDecode,
			(xbytesview) { arrGzip, sizeof(arrGzip) }, true,
			exampleOutput, (ptr)&Out) ||
		!xrtHttpDecodeDone(pDecode) ||
		(Out.iBytes != 26u) ||
		(memcmp(Out.arrText, "identity-passthrough-check",
			26u) != 0) ||
		(xrtHttpDecodeInputSize(pDecode) != 46u) ||
		(xrtHttpDecodeOutputSize(pDecode) != 26u) ) {
		goto Cleanup;
	}
	printf("decode: gzip content mode + input/output sizes ok\n");

	/* ---- Reset 换 identity 字段：窗口复用 + 透传模式。 ---- */
	Fields[0].Value = XRT_STR_LITERAL("identity");
	memset(&Out, 0, sizeof(Out));
	if ( !xrtHttpDecodeReset(pDecode, Fields, 1u, &Compat) ||
		(xrtHttpDecodeMode(pDecode) != XHTTP_DECODE_IDENTITY) ||
		!xrtHttpDecodeWrite(pDecode,
			(xbytesview) { arrGzip, 4u }, true,
			exampleOutput, (ptr)&Out) ||
		!xrtHttpDecodeDone(pDecode) ||
		(Out.iBytes != 4u) ||
		(xrtHttpDecodeInputSize(pDecode) != 4u) ) {
		goto Cleanup;
	}
	printf("decode: reset to identity passthrough ok\n");
	iResult = 0;

Cleanup:
	xrtHttpDecodeDestroy(pDecode);
	return iResult;
}