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authorAndrea Marchesini <amarchesini@mozilla.com>2020-07-29 10:52:30 +0000
committerMoonchild <moonchild@palemoon.org>2020-07-29 14:28:45 +0000
commit3323a8eda3d4cbb29909f6761cee96cc5e164cf2 (patch)
treee2b69428455e26be4e48d75c99e407825b2a4f99 /xpcom/io/Base64.cpp
parent71293f0fe4db15d4e0309488337ab4669e9c55b3 (diff)
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[xpcom] Make Base64 compatible with ReadSegments() with small buffers.
Diffstat (limited to 'xpcom/io/Base64.cpp')
-rw-r--r--xpcom/io/Base64.cpp32
1 files changed, 25 insertions, 7 deletions
diff --git a/xpcom/io/Base64.cpp b/xpcom/io/Base64.cpp
index 911c0595a..b9fa7baf8 100644
--- a/xpcom/io/Base64.cpp
+++ b/xpcom/io/Base64.cpp
@@ -108,30 +108,51 @@ EncodeInputStream_Encoder(nsIInputStream* aStream,
EncodeInputStream_State<T>* state =
static_cast<EncodeInputStream_State<T>*>(aClosure);
+ // We always consume all data.
+ *aWriteCount = aCount;
+
// If we have any data left from last time, encode it now.
uint32_t countRemaining = aCount;
const unsigned char* src = (const unsigned char*)aFromSegment;
if (state->charsOnStack) {
+ MOZ_ASSERT(state->charsOnStack == 1 || state->charsOnStack == 2);
+
+ // Not enough data to compose a triple.
+ if (state->charsOnStack == 1 && countRemaining == 1) {
+ state->charsOnStack = 2;
+ state->c[1] = src[0];
+ return NS_OK;
+ }
+
+ uint32_t consumed = 0;
unsigned char firstSet[4];
if (state->charsOnStack == 1) {
firstSet[0] = state->c[0];
firstSet[1] = src[0];
- firstSet[2] = (countRemaining > 1) ? src[1] : '\0';
+ firstSet[2] = src[1];
firstSet[3] = '\0';
+ consumed = 2;
} else /* state->charsOnStack == 2 */ {
firstSet[0] = state->c[0];
firstSet[1] = state->c[1];
firstSet[2] = src[0];
firstSet[3] = '\0';
+ consumed = 1;
}
+
Encode(firstSet, 3, state->buffer);
state->buffer += 4;
- countRemaining -= (3 - state->charsOnStack);
- src += (3 - state->charsOnStack);
+ countRemaining -= consumed;
+ src += consumed;
state->charsOnStack = 0;
+
+ // Bail if there is nothing left.
+ if (!countRemaining) {
+ return NS_OK;
+ }
}
- // Encode the bulk of the
+ // Encode as many full triplets as possible.
uint32_t encodeLength = countRemaining - countRemaining % 3;
MOZ_ASSERT(encodeLength % 3 == 0,
"Should have an exact number of triplets!");
@@ -140,9 +161,6 @@ EncodeInputStream_Encoder(nsIInputStream* aStream,
src += encodeLength;
countRemaining -= encodeLength;
- // We must consume all data, so if there's some data left stash it
- *aWriteCount = aCount;
-
if (countRemaining) {
// We should never have a full triplet left at this point.
MOZ_ASSERT(countRemaining < 3, "We should have encoded more!");